Posted once before but need suggestions

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MvJackson

MvJackson

72duster
Joined
Mar 26, 2015
Messages
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Location
Mesa, AZ
Upgrading my 72 slant six.

I am looking into a shift kit, headers, exhaust(dual out the back kit preferred) intake and 2 bbl carb.

What products are recommended? Best performance. Engine runs strong just want to give it a little extra hp.

If you have links that'd be great.

Thanks guys!
 
back in the 70s i put a 318 2 bbl carb on a stock 64 slant 6. nothing else. be for chrysler did it. it was like adding an other engine. its a long story. i did lots of things diff than chrysler did. the most important was the carb setting. i put the carb throttle shaft facing front to rear, this makes the fuel distribution better. the MOST important thing is that the throttle does NOT stick at WOT.
 
If you do some reading you'll find that a good high performance single exhaust works better for the slant.
 
You didn't say, but i'm assuming your '72 /6 is in a '72 body,in which case check out the
mech parts 4 sale. dartman65 had/has an excellent JR/hedman 6 into 1 MP header for
sale, may not make as much ultimate HP as 6 into 2 into1 will,but more than enuff 4 your
goals. rusty's rite & if you insist on dual TP's split 'em out back. 318 carb on supersix
intake is fine if you re-jet accordingly,non-feedback holley if poss.
If you were willing to pull the head, milling the surface .060, and getting a fresh valve
job back cutting the valves will pretty much be the most bang for the buck w/o getting
into expensive stuff.(cams, OS valves & springs,porting etc.).
the /6 bore is small, & plug location decent, so the bump in comp. ratio won't be an issue
& worth steppin up some octane for. :)

PS if you do the head mill & or valve job don't forget to back off your rocker screws 1 1/2 turns B4 re-installing the rocker shaft! Cheers!
 
Brandon Weaver said:
Just curious, why do you want headers?
Click to expand...

I'm rather new to this.
A friend told me headers would help.
If it's not necessary with moving up intake and carb then I wont. I do want to put less restricted exhaust.

Not 100% sure what all I'm going to do.
Just looking for tips on beefing it up a bit
 
MvJackson said:
I'm rather new to this.
A friend told me headers would help.
If it's not necessary with moving up intake and carb then I wont. I do want to put less restricted exhaust.

Not 100% sure what all I'm going to do.
Just looking for tips on beefing it up a bit
Click to expand...

It sounds to me like you don't have an actual goal here, which makes it difficult to help
you. Why would you want a header?, um because it's proven to be the best first step
in improving power,torque, & efficiency time& time again. BUT headers come w/some hassles you may or may not want to deal with.Dutra duals are a great 2nd choice but give
up some of the great torque the header offers for more reliable sealing etc. supersix int.
manifolds are still falling out of peoples rafters & are for sale elsewhere on this site, get
one! you ain't gettin no beef w/o more air&fuel! Ditto 2bbl. carter& holley carbs but you
need to re-jet, just curious, your new to working on cars in general or....?
 
You're in luck. The 71 through 77 /6s have the best camshaft Mopar installed in it. The specs on the cam are 244º/244º/26º with lifts of .406/.414. Mopar used to make a pair of camshafts for the engine, but the specs on the current models look like they are using repackaged Comp Cams. Comp Cams makes 4 cams (2H, 2S) that are stock item for them. (264º/264º/?? .440/.440.)A few years back, the guys over at Slantsix.org came up with a group order from Sig Erson. IDK the specs on it.
Good luck finding headers for the slant six. IDK if Hedman has produced any for the /6 in this millennium. There is a group in Australia that is making a set that lends itself very well for dual exhausts. http://www.ebay.com/itm/slant-6-mop...six-/371184135767?hash=item566c4c6e57&vxp=mtr . Dutra Duals are a good choice, too.
Another you might consider are made by Moparsnmore.us/exhaust.html. These are like the Dutra Duals but with larger passages. The guy who makes them got roughed up here and over on slantsix.org essentially for making performance claims at the time without providing instrumented tests to back them up. Look at them as an oversized Dutra Duals and you'll have realistic expectations. I've been using a single outlet product in combination with a 2¼" exhaust for the past six years on a street car with no issues.
One of the things to consider when making changes to the exhaust and intake, especially if you live in a northern climate is having a provision for heating the carburetor during when the engine is cold. With my setup the engine is hard to keep lit until the manifold warms up a bit.
If you can't find a 2bbl intake, try AussieSpeed. The runners on their manifold are longer than the Super Six, so you'll need a kickdown cable.
I left the /6 tranny alone in my 73. My 72 runs a 904 with a TransGo TF2 shift kit in it. It firms shifts up nicely. For what it does, it was a good change to make IMHO.
 
Alright, I guess I'll toss in my 2 cents on this one.

First of, I'd stay pretty far away from comp's cams. I haven't heard much negative on the V8 cams, but I've heard nothing but bad in the past 4 years or so for the slant. That, and they have a horrible selection for cams.

The better option? Oregon Cam Grinding. Pretty much the go-to cam shop over at .org (seriously, they've even made rollers for the slant. no you don't need or want one) Here's their website: www.oregoncamshaft.com but it don't have much other than contact info. How many/what slant cams do they have? I couldn't quite get it to work, looks like you've gotta copy/paste it... app.box.com/s/a00t8svaib0jqevitapq (This is a few years old, the newer/more updated one I couldn't get to work)

Personally, I'd say between 718 and 819 would work for you. 819 is pretty much a Comp 264 copycat, and is the most you'd want with a stock stall, from my understanding.

Exhaust wise, I'd go one of two ways. The easier and cheaper way would be hog out your current exhaust manifold. 2.25" outlet with a gasket match at the head mating surface would be a nice step up. Use with 2.25" pipe and muffler of choice, split for dual tailpipes if so desired.

Option two I'd go with a Dutra front casting, 2" head pipes to a Y about 36-40" back This is supposed to provide more torque than true duals, and again you can split it out back if ya want. Headers are nice, and give more undisputed power, but I wouldn't want to put up with the poor cold manners, rusting/poor sealing, excess heat, and whatnot. Not to mention the price!

If you can't find a 2 barrel setup for under $250, I'd start the hunt for an Offy 4 barrel and a 390cfm vacuum secondary. I wouldn't go the AussieSpeed route. It's an overpriced ($600!) fancy looking intake that has no provisions for carb heat, doesn't perform any better than the Offy as far as I know, is a pain to package (Hope you don't have power brakes!) and long runner intakes generally need to be richer to maintain driveability, causing poor fuel economy and more engine wear.

Lets see... you need more compression, and more headflow as well. Shave the head .050-.075 for the compression part (you actually need to measure stuff for best results, you want ~9:1 compression) and take a Dremel to the lumps around the valve guides if you feel really bold (It ain't hard to screw things up there, but gains are to be had. Do at your own risk).

Stall, gears, and a shift kit would be icing on the cake. It's only money and labor after all! That's what you will find when it's all said and done. Slants have a little different needs than a V8, and don't make the power, but if you're into them they can be fun to tinker with.

Have fun!
 
Killer6 said:
It sounds to me like you don't have an actual goal here, which makes it difficult to help
you. Why would you want a header?, um because it's proven to be the best first step
in improving power,torque, & efficiency time& time again. BUT headers come w/some hassles you may or may not want to deal with.Dutra duals are a great 2nd choice but give
up some of the great torque the header offers for more reliable sealing etc. supersix int.
manifolds are still falling out of peoples rafters & are for sale elsewhere on this site, get
one! you ain't gettin no beef w/o more air&fuel! Ditto 2bbl. carter& holley carbs but you
need to re-jet, just curious, your new to working on cars in general or....?
Click to expand...


Yeah I've done some work on cars in the past.

Never tried to change anything out on a car that wasn't stock.
I appreciate all the help.
 
When I had my ex's slant rebuilt, I called Dave Crower and he made a nice custom cam for her. It runs great and she's happy with it...
 
alrighty then, I guess we need parameters for what you & those that might help you,
are willing to tackle.First, I incorrectly id'd 65dartman , he has the well made 6 into 1
header for sale in the mech. parts forum. probably several pages back or more now.
the header has a 3" collector, so if you start out mild & run a 2 1/2 exh or so, you have room to step up. performance wise, they will be superior to the other options, & this 2nd
version mopar perf. sold is much higher quality than the 1st. I had no real issues w/mine
other than the usual for headers, putting some clearance dings here & there, and make-
ing sure to route things safely away from the hot tubes. collector gasket leaks are
universal but any competent welder can put a ball & flange setup to fix that for you.
If you are running an auto trans, your biggest job will be to hook-up the brackets
& throttle pressure linkage so that it functions correctly.Getting an entire setup from
a donor car is the way to go, and they have also been offered on the above forum here.
there have been posts w/ good info for you here,(didn't know about the OTHER cast
duals out there,thx 4 that), and alot of it is in the direct connection/mopar performance
eng books. Unfortunately, ma mopar seems to have abandoned /6 fans in the parts dept., as well as 2.2/2.5 fans so we are on our own. Hughes is now offering their cam
profiles taking advantage of mopars large lifters for the /6 :), I may get their replace-
ment for my disc,'d 276/.490 purple shaft, ......... so what say you Myjackson?
Whatever you want to tackle, there are those here who have done it, we can help
so lets do it!
 
To this point, all of us that have of us that have posted have focused on bolt-on speed items. If you are willing and able to pull the engine and take it apart,, there are some real power gains to be had. A quick clean up of the head passages and combustion chambers can be done at home. The big gain comes from milling the head and/or block. Mopar recommends a maximum cut of .090" on either. Others here and on slantsix.org have reported going farther. though some have reported the need for shorter pushrods or shimming the rocker shaft. Assuming a compressed gasket thickness of .020, Mopar reports to 9.5:1 CR with a 1" deck height for the 225. This plays well with pump gas.
 
OK 2 darts we're waiting on Myjacksons reply as to his goals,abilities,help,and budget
for that matter. In the meantime remove the handyman's secret weapon from your
eyes & reread our posts above:)! I mentioned/recommended milling the head in my
1st post, and the.060" because thats about as much as the adj. screw on the rockers
want b4 the pushrod cup gets too close to hitting the arm, esp. if you add a cam w/any
lift. My eng. cc'd at 9.37:1 w/ stock .060 over pistons & enuff off the head&deck that the
pushrod cups were against the rocker b4 it even started lift. They were crane chromolly
I pulled the ends, cut down the length, & pressed them back in. There is a ton of
performance in the heads, but other than putting bigger valves in w/a perf, valve job,
mods should be left to the pros. any mach. shop can do this and it is well worth it even
w/o porting. just blending the cut to bowl is enuff here.I doubled the flow of a slant int.
port using a 1.88 max wedge exh. valve years ago, & judging by what i've read about
other attempts by Sheradon,Engines West, etc. , I believe I'm spot on that that's the
most you'll get from one w/o crazy outwelding etc. stock is approx 97 & the best #'s
i've seen are in the low 200's, which is excellent for the valve size in these bores btw.
Folks here like charlie s & others have been racing these things a long time, so if you
know what you're after mild to wild, there are people here & /6.org to guide you, ok
MyJackson ........ lets have it:happy1:
 
Killer6 said:
remove the handyman's secret weapon from your
eyes
Click to expand...

Sorry for missing mill comments in the other posts. :eek:ops: But secret weapon?? Hell, that's half of a backwoods/redneck tool box contents. It works like this: If it moves and should not, use the tape; if it doesn't move and should, use WD-40. :)
 
Killer6 said:
OK 2 darts we're waiting on Myjacksons reply as to his goals,abilities,help,and budget
for that matter. In the meantime remove the handyman's secret weapon from your
eyes & reread our posts above:)! I mentioned/recommended milling the head in my
1st post, and the.060" because thats about as much as the adj. screw on the rockers
want b4 the pushrod cup gets too close to hitting the arm, esp. if you add a cam w/any
lift. My eng. cc'd at 9.37:1 w/ stock .060 over pistons & enuff off the head&deck that the
pushrod cups were against the rocker b4 it even started lift. They were crane chromolly
I pulled the ends, cut down the length, & pressed them back in. There is a ton of
performance in the heads, but other than putting bigger valves in w/a perf, valve job,
mods should be left to the pros. any mach. shop can do this and it is well worth it even
w/o porting. just blending the cut to bowl is enuff here.I doubled the flow of a slant int.
port using a 1.88 max wedge exh. valve years ago, & judging by what i've read about
other attempts by Sheradon,Engines West, etc. , I believe I'm spot on that that's the
most you'll get from one w/o crazy outwelding etc. stock is approx 97 & the best #'s
i've seen are in the low 200's, which is excellent for the valve size in these bores btw.
Folks here like charlie s & others have been racing these things a long time, so if you
know what you're after mild to wild, there are people here & /6.org to guide you, ok
MyJackson ........ lets have it:happy1:
Click to expand...

At this point I drive it everyday. I basically wanted to get some parts for the engine to help it have a little more power. Carb, intake. 2 or 4 barrel? headers etc. just seeing if anyone has Isuggestions on certain brands/models. Combinations and such.
 
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