'70 Dart 392 Project; what direction?

[208Dart]

Hey guys, been cruising the forums for a couple weeks now, enjoying seeing all the projects and been heavily using the search function. Have some questions though if you'd help a guy out! Sorry in advance for the long winded post.

Drove 1800 miles round trip a few weeks ago and picked up a beautiful '70 Dart swinger (will post some pics from my phone after this) in eastern California. Bought the car with no motor/trans, but "fresh" 12 year old paint though the car was never fully assembled after that. It's got the original /6 K member in it and a 7 1/4 rearend. Have all the glass (tinted already), headliner kit, carpet kit, trim pieces....etc Needs the bench seats recovered but a great starting point.

Anyways, I've since then acquired a 1970 Duster 4 speed A833/SB bell housing setup complete with the floor plan/trans crossmember and pedal assembly. As well as some V8 Torsion bars.
I also two weeks ago found a burned up 6.4 BGE engine. When I say burned up, the 2014 pickup it came from had a cab fire. It melted the intake cover and damaged a lot of the accessories. Price was right at $800 however so I snagged it. Got the heads dropped off at a local shop to be inspected and resurfaced, will be dropping the block off to be hot tanked this week as well, top of cylinders looked really good so hoping for just a re-ring and hone job. Also picked up an SRT8 complete intake with fuel rails/injectors/throttlebody. Owner of the intake said it has "6 wire" injectors which are bigger than the "4 wire" injectors... I still see a 2 pronged electrical connector so not sure what he's referring too...

So far my plan is to use the holley Midmount front cover/accessory package since the original accessories were trashed from the cab fire.

I've also got a cam/valvespring/VVT lock kit coming from MMX. Should be here this week. MMX has said that with a decent tune, headers and this Cam with the 9.5 compression ratio BGE Truck block that 450-500 whp is what I should expect.... crazy town, I was hoping for somewhere in the 375-400whp when I started this project.

First questions deals with the front suspension, this is a long term project (been waiting 17 years to pick up another mopar project, want to do things right). I have a box of front suspension parts from the previous owner for a front disk brake setup, haven't inventoried them however. FYI front suspension systems are probably the area that I need to improve my knowledge on the most! So please bear with me.

Option 1 for front: Use OE type suspension, swap to a V8 K member and TTI mounts (have a V8 K member at a friends), upgrade to the smaller borgeson power steering pump, remote oil filter setup, TTI headers, Holley cast aluminum oil pan, and figure out how to make the factory steering system work with the oil pan clearance issues for the 68-72 setup. Another option is to find and "upgrade" to the '73 steering system that has the linkages pointing "down" that will clear the oil pan. Then use my OE type disc brake conversion. I've been advised to atleast upgrade to adjustable tubular upper control arms to help brings things into alignment and improve handling, as well as gusset and reinforce my OE lower control arms.

Question: Has anyone run the mini borgeson pump with the holley midmount accessories and factory K member? Is it a no-go or will it be feasible? I can cut and reweld anything, so if some minor clearancing is needed than no problem. Even if it's not a "bolt in" guarantee.

Option 2 is to save up for a while longer and go with a complete HemiDenny front K member suspension/coilovers.... This seems like the most simple option, however it definitely isn't cheap especially with the disc brake/coil over/R&P steering setup. Long term when comparing costs it may just be the smarter route to go. Time is money and if I will continue to rework every component of the front suspension/steering system, then this is a favorable upgrade.

Option 3 is to use the QA1 tubular front K member and piece together the needed parts to complete the setup. I can TIG weld and I have a fairly complete cnc/manual machine shop that I run for my own business, so fabricating skills are there, however the knowledge of steering geometry and what is appropriate to adapt is what I don't know. Would this front K member combined with the factory torsion bars and steering linkages be a viable option? They say it's a "drop in" K member.

I've seen the R&P steering setups condemned on this board, and I've seen them praised.... Not sure what to think about them! Would adapting a Dakota or similar setup be a smart decision? That borgeson pump isn't cheap... but my wife will sometimes drive this car and power steering is a must, or at least "low effort" steering is a must.

Few random questions for the other areas of the build:

Megasquirt vs. Holley Dominator EFI, I've installed and have dealt with the MS platform before and am fairly confident in it. Does the holley system allow the same tunability as the MS system? Any preferences? Does the MS support the drive by wire TB?

Rear suspension/traction issues: How the heck can I expect to hook up 450-500 whp on the street? I'll be building my own rearend for the car, planning a minitub and likely offset spring shackles, along with 3:23 gears and a narrowed housing. Since the suspension will be modified heavily anyways, should I be thinking about going to a 4 link rear? Or can I run say the Hotchkis springs and a good shock setup?

I appreciate any info. It will likely be mid summer before I'm finished with the engine build and am able to start test fitting the drivetrain, so until then asking questions is the only way I know to start putting together a gameplan.

Mike

 

[70dart340]

Watching. I'm building a 408 stroker with TF heads to put in my 1970 Swinger 340. I'm following your build.

 

[208Dart]

Watching. I'm building a 408 stroker with TF heads to put in my 1970 Swinger 340. I'm following your build.

Copy that here’s a few pics as mentioned from when I brought the car home!

 

[TT5.9mag]

Nice car for sure. My vote is for the @HemiDenny front end option. Sell off all the other parts to outweigh the cost. His front ends are extremely nice and well thought out. The only way you can correctly put a rack in these cars is to replace the front end completely. As to the rear, a set of monoleafs and caltracs or assassin bars with a mini tub and decent tires will hook up just fine at 500hp with some decent shocks. Happy hot rodding

 

[TT5.9mag]

On the Holley vs MS topic, pick whichever one you are more familiar with. The MS will do everything that a Holley will do but may require more effort on your part. The Holley is a more plug and play option.

 

[208Dart]

Nice car for sure. My vote is for the @HemiDenny front end option. Sell off all the other parts to outweigh the cost. His front ends are extremely nice and well thought out. The only way you can correctly put a rack in these cars is to replace the front end completely. As to the rear, a set of monoleafs and caltracs or assassin bars with a mini tub and decent tires will hook up just fine at 500hp with some decent shocks. Happy hot rodding

As busy as I am with my own business, time is $$$ and a complete system like the HD is looking more and more attractive. If I could sell everything else I've got for even 20-25% of the cost I'd go that route.

On the Holley vs MS topic, pick whichever one you are more familiar with. The MS will do everything that a Holley will do but may require more effort on your part. The Holley is a more plug and play option.

I am more familiar with the MS but haven't tuned anything on it. I megasquirted a '79 Ramcharger of mine back when I was 16 (17 years ago) with a chevy 350 TBI setup. It ran good but it was tuning on a very very basic level. They're lightyears ahead of where they were. My buddies '70 Duster is running MS on a boosted slant 6 and I'll be helping him with the tuning here in the coming months. Will give me a better idea if I want to go that route.

How do the mono's ride on the street? Although I'm sure anything will be better than my 1 ton daily driver at this point...

Still curious if anyone has ran a QA1, Holley midmount, Borgeson box and kept the torsion bars...?

Mike @ HCA

 

[1973Barracuda]

When you pick your steering box make sure you match your headers to it. I bought mine before I decided on my steering box and was kind of cornered. I am referring to tti headers.

 

[208Dart]

Got the block stripped down tonight. Cam and valve springs will be here Friday. Taking the block to get hot tanked and inspected tomorrow. Cylinder walls look good, had the slightest groove on a rod bearing. Will inspect it more closely… hoping it’ll be alright with a polish and new bearings.

Also, what’s up with the red coated main bearing? Never seen that before…

 

[208Dart]

Couple more pics of two journals. First is rod journal previously mentioned, and second is main journal. I don’t know how critical the wear pattern is. The rod journal is less than .0005” deep for sure, can’t click it with a fingernail.
The main journal just seems like a wear pattern. I believe it would take between 2 and 5 tenths to polish out from my machining experience.

Do you think these warrant anything other than a polish and new bearing?

Mike

 

[208Dart]

While I'm waiting for machine shop to hot tank my block and rods, I'm doing some more research. Currently saving up for the HemiDenny K member kit, but want to get my block and trans buttoned up before purchasing. Still need to purchase holley midmount setup as well as an oilpan/pickup assembly and valvecovers.

Has anyone used these manifolds? I wouldn't mind saving the cash on the headers, and with a R&P steering and coilovers I don't see why these wouldn't work? Any insight?
Jeep Grand Cherokee SRT Exhaust Manifold Kit - 77072462AB

Thanks much.

Mike

 

[toplscuda]

I have a set on my 6.1 with an alterkation. I had to modify the drivers side mount to get it to clear. With that you can use a 5.7 manual trans oem truck starter which tucks up against the block tightly

 

[208Dart]

I have a set on my 6.1 with an alterkation. I had to modify the drivers side mount to get it to clear. With that you can use a 5.7 manual trans oem truck starter which tucks up against the block tightly
View attachment 1715911113

Looks like those are the factory SRT8 Jeep manifolds? They look great. For the drivers side mount, did you have to cut and reweld or just clearance?

Also, were you able to use the factory oil pan?? Looks like it in that picture... $450 for the holley cast pan is a tough pill to swallow.

Thank you!

Mike

 

[toplscuda]

I did cut the clearance and weld in a solid piece of steel in the lower part. The pan is a factory truck pan as is the dipstick. Haven't installed it in the car yet but it doesn't really hang any lower than a deep sump pan so I do not expect any issues. when I bought it the factory pan was less than $100

 

[toplscuda]

 

[208Dart]

I did cut the clearance and weld in a solid piece of steel in the lower part. The pan is a factory truck pan as is the dipstick. Haven't installed it in the car yet but it doesn't really hang any lower than a deep sump pan so I do not expect any issues. when I bought it the factory pan was less than $100

Perfect answer thank you. There’s $450 I can put towards front suspension…. I’ll contemplate the SRT manifolds vs headers. Can’t imagine the power loss being that significant although I am running a .610”+ lift cam….

Mike

 

[208Dart]

I did cut the clearance and weld in a solid piece of steel in the lower part. The pan is a factory truck pan as is the dipstick. Haven't installed it in the car yet but it doesn't really hang any lower than a deep sump pan so I do not expect any issues. when I bought it the factory pan was less than $100

One more question for you. What year A body are you installing in and what’s your planned steering setup? Rack and pinion or factory/manual/power? Thanks

Mike

 

[toplscuda]

Mike
It is going in a 68 Barracuda convertible. Alterkation with a power rack

 

[208Dart]

Updates so far, machine shop didn’t have the right sized bearing installation bodies so I machined some for his installation tool. Had to replace the cam bearings due to their hot tank being corrosive towards aluminum.

i got the block back today as it needed more cleaning. Whatever kind of “paint” they use on these blocks isn’t easy to get off! Used some abrasive pads on a die grinder. Took it back to the shop for a final hot tank and then cam bearing install.
Machinist said the bores spec’d out within 2 tenths of factory minimum so that’s a win. Rod ends also spec’d out perfect. Should have it back by the weekend and can start on shortblock assembly.

Also talked with Denny and ordered a full front end suspension kit through him. Power R&P, steering shaft connection, front sway bar, drop spindles, mounts/coils/shocks…etc looking forward to receiving it!

couple pics:
Engine when I first bought it, salvaged from an engine fire…

prior to cleanup this AM.

after cleanup ready for a final bath.

Mike

 

[racerjoe]

Hey guys, been cruising the forums for a couple weeks now, enjoying seeing all the projects and been heavily using the search function. Have some questions though if you'd help a guy out! Sorry in advance for the long winded post.

Drove 1800 miles round trip a few weeks ago and picked up a beautiful '70 Dart swinger (will post some pics from my phone after this) in eastern California. Bought the car with no motor/trans, but "fresh" 12 year old paint though the car was never fully assembled after that. It's got the original /6 K member in it and a 7 1/4 rearend. Have all the glass (tinted already), headliner kit, carpet kit, trim pieces....etc Needs the bench seats recovered but a great starting point.

Anyways, I've since then acquired a 1970 Duster 4 speed A833/SB bell housing setup complete with the floor plan/trans crossmember and pedal assembly. As well as some V8 Torsion bars.
I also two weeks ago found a burned up 6.4 BGE engine. When I say burned up, the 2014 pickup it came from had a cab fire. It melted the intake cover and damaged a lot of the accessories. Price was right at $800 however so I snagged it. Got the heads dropped off at a local shop to be inspected and resurfaced, will be dropping the block off to be hot tanked this week as well, top of cylinders looked really good so hoping for just a re-ring and hone job. Also picked up an SRT8 complete intake with fuel rails/injectors/throttlebody. Owner of the intake said it has "6 wire" injectors which are bigger than the "4 wire" injectors... I still see a 2 pronged electrical connector so not sure what he's referring too...

So far my plan is to use the holley Midmount front cover/accessory package since the original accessories were trashed from the cab fire.

I've also got a cam/valvespring/VVT lock kit coming from MMX. Should be here this week. MMX has said that with a decent tune, headers and this Cam with the 9.5 compression ratio BGE Truck block that 450-500 whp is what I should expect.... crazy town, I was hoping for somewhere in the 375-400whp when I started this project.

First questions deals with the front suspension, this is a long term project (been waiting 17 years to pick up another mopar project, want to do things right). I have a box of front suspension parts from the previous owner for a front disk brake setup, haven't inventoried them however. FYI front suspension systems are probably the area that I need to improve my knowledge on the most! So please bear with me.

Option 1 for front: Use OE type suspension, swap to a V8 K member and TTI mounts (have a V8 K member at a friends), upgrade to the smaller borgeson power steering pump, remote oil filter setup, TTI headers, Holley cast aluminum oil pan, and figure out how to make the factory steering system work with the oil pan clearance issues for the 68-72 setup. Another option is to find and "upgrade" to the '73 steering system that has the linkages pointing "down" that will clear the oil pan. Then use my OE type disc brake conversion. I've been advised to atleast upgrade to adjustable tubular upper control arms to help brings things into alignment and improve handling, as well as gusset and reinforce my OE lower control arms.

Question: Has anyone run the mini borgeson pump with the holley midmount accessories and factory K member? Is it a no-go or will it be feasible? I can cut and reweld anything, so if some minor clearancing is needed than no problem. Even if it's not a "bolt in" guarantee.

Option 2 is to save up for a while longer and go with a complete HemiDenny front K member suspension/coilovers.... This seems like the most simple option, however it definitely isn't cheap especially with the disc brake/coil over/R&P steering setup. Long term when comparing costs it may just be the smarter route to go. Time is money and if I will continue to rework every component of the front suspension/steering system, then this is a favorable upgrade.

Option 3 is to use the QA1 tubular front K member and piece together the needed parts to complete the setup. I can TIG weld and I have a fairly complete cnc/manual machine shop that I run for my own business, so fabricating skills are there, however the knowledge of steering geometry and what is appropriate to adapt is what I don't know. Would this front K member combined with the factory torsion bars and steering linkages be a viable option? They say it's a "drop in" K member.

I've seen the R&P steering setups condemned on this board, and I've seen them praised.... Not sure what to think about them! Would adapting a Dakota or similar setup be a smart decision? That borgeson pump isn't cheap... but my wife will sometimes drive this car and power steering is a must, or at least "low effort" steering is a must.

Few random questions for the other areas of the build:

Megasquirt vs. Holley Dominator EFI, I've installed and have dealt with the MS platform before and am fairly confident in it. Does the holley system allow the same tunability as the MS system? Any preferences? Does the MS support the drive by wire TB?

Rear suspension/traction issues: How the heck can I expect to hook up 450-500 whp on the street? I'll be building my own rearend for the car, planning a minitub and likely offset spring shackles, along with 3:23 gears and a narrowed housing. Since the suspension will be modified heavily anyways, should I be thinking about going to a 4 link rear? Or can I run say the Hotchkis springs and a good shock setup?

I appreciate any info. It will likely be mid summer before I'm finished with the engine build and am able to start test fitting the drivetrain, so until then asking questions is the only way I know to start putting together a gameplan.

Mike

I run MS3X on my 408 small block. I'm using it for sequential fuel and spark, along with several of the inputs/outputs, such as fan control, AC idle up, traction control, etc. I really like the Holley digital dashes and their tuning software seems more intuitive than Tuner Studio. The "cheaper" route is to use the terminator X, but the inputs/outputs are limited unless you use their CAN bus I/O extender. If you are just looking for something that will make the engine run, Terminator X is likely the way to go. The Terminator X Max will do DBW throttle. The Dominator will have many more options for I/O, but that comes at a significant cost over MS. I did see Holley just released smart coils for the G3 platform which is really cool, but I'm sure the cost of those far exceed the cost of just using the external coil ignitor. I go back and forth over switching to Holley or keeping the MS. I would most definitely need to use the I/O extender on the Terminator to make everything I already have continue to work.

For your rear suspension question, it really depends on your intended use of the car. Nothing beats the simplicity of just putting leaf springs back in the car. I run Hotchkis springs and the ride height is good and the ride is great. Handling is amazing for a 50 year old car. if you are building a drag car, Calverts are likely the way to go. It sounds like you are building a car to cruise, not race, so some good leaf springs would be my vote. And if you aren't racing, does traction really matter? Sounds like you plan to put a decent tire under it, which will help with traction. While 500Hp is enough to turn the tire, it's not like you will be driving on ice with the small touch of the throttle. If it's too much, put traction control on it, you will have an ECU capable of doing it whichever route you go.

 

[Kiddart1]

I run the MS3 Gold box and its been really good. I have been hands off while my son has been tuning with help from a gentlemen that lives in Canada. between them the car runs fantastic and we have a little more tuning to go and then turn the wick up!!

 

[208Dart]

Thank you for the input! I have some time to figure out what direction to go on rear suspension but you make a good point about cruising vs racing. My buddies 70 duster has hotckiss rear springs and front suspension upgrades and it handles extremely well! Traction control and a fat tire is something to think about.
I’m fairly set on megasquirt and a new throttle body. After tuning through tuner studio on a friends car and helping him wire it up I’m not too worried about it. Pretty straight forward. Especially since I’m not running nitrous or forced induction.
I should have my shortblock assembled this weekend. Need to pickup a few things at the dealer (rod bolts and the freeze plug that covers the rear cam bearing). Hopefully have my heads back this week as well. I still need my holly mid mount setup, oil pan (waiting on k member first to see if there’s any chance of factory pan working with the power rack n pinion), and brewers performance flywheel and clutch setup for my 833.
Don’t judge me too hard but I bought Chevy orange engine paint…. ‍ Seemed like the closest match to the body color lol

Mike

 

[208Dart]

Anybody have any preference for the TTI headers vs. the Holley Blackheart headers? Only reason I'd run TTI I think is for the 3" collectors... Really not sure why Holley would run 2.5" on a G3 header like that. Holley midmount accessory package should be here next week. Probably done buying parts for a bit until I get engine assembled and onto the new K member.... maybe

Mike

 

[DionR]

Anybody have any preference for the TTI headers vs. the Holley Blackheart headers? Only reason I'd run TTI I think is for the 3" collectors... Really not sure why Holley would run 2.5" on a G3 header like that. Holley midmount accessory package should be here next week. Probably done buying parts for a bit until I get engine assembled and onto the new K member.... maybe

Mike

I don't have any experience, but be aware that the Holley headers are designed around the motor being several inches forward of where an LA would be mounted. This was to clear the SVR setup on the 6.4 intake and the IC coolant manifold on the Hellcat motor.

No idea if the Holley ones would work outside of their motor location. Just pointing it out.

 

[208Dart]

I don't have any experience, but be aware that the Holley headers are designed around the motor being several inches forward of where an LA would be mounted. This was to clear the SVR setup on the 6.4 intake and the IC coolant manifold on the Hellcat motor.

No idea if the Holley ones would work outside of their motor location. Just pointing it out.

Solid info, I just talked to a Tech at Holley and he wasn't very helpful... no more info gleamed than whats on the website. Unfortunate because they offer a 3" collector header for the B/E body but only 2.5" for the A body. Not sure if the B/E body would work or not with the HDK K member and Power R&P steering... leaning towards TTI for this.

Also having a hard time sourcing lifters. MMX has them but they're expensive. Had some backordered at Summit but now they're out until middle or end of August which is a bit too far out for myself. Assuming I can reuse my factory lifter yokes so just wanting to replace the 16 lifters. Or should I just order the individual NON-MDS lifters and reuse factory ones? Not too excited about reusing factory lifters, but could be worried for nothing....?

Thanks for the help guys.

Mike @ HCA

 

[208Dart]

Got lifters ordered from MMX as well as the MDS plugs and 45* oil filter mount adapter. got the rotating assembly put together last night. FYI check your ring gaps! Ordered factory replacement rings and they were ALL a .000-.005” gap. Even the oil scraper rings were set at a zero gap. Mahle rings were supposed to be factory replacement. Took some time to get them all gapped correctly but install when pretty good. Crank endplay was right at .006” so good to go there.

Hoping to finish off cam and timing chain install this evening.

Mike