I really need some advice here

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999yards

999yards

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I have searched and read so much that I now cant seem to figure out what the best route is. So here is what I have to work with.

I have a 66 Barracuda with a good strong 727, 8 3/4 with 3:73 sure grip, heavy duty rear springs and shocks, front and rear sway bar.

Engines I have to build from.
A 1994 5.2L magnum. complete runs good

A 1991 360 out of a Dodge 3500.

I already know that both are roller engines and the 1991 360 has the 308 type heads.

Suggestions on which engine to build or mix the two.

Don't mind doing head work or putting larger crank in either. Or putting nitrous on a de stroked. I know the longer stroke puts out more torque lower in the rpm range but don't want the *** end to come around on me when I stomp it.


What I want to end up with is a car that will launch from about 3000rpms to 7000rpms.

Not looking for hole shots or running at the track. Just want to knock the hell out of one of those new Camaros, mustangs, ect when they pull up beside me while going down the road.

Thanks in advance
 
The cars *** coming out from under you and getting in front of you is a suspension traction issue. Not a HP/torque issue.

My advice is build the 1991 "LA" roller block and upgrade the heads later. Ported 308's are fine. And since your doing that work, cheap! Building a Magnum engine limits your heads to Magnum only heads. The problem is the lack of a block oil passage for the more common "LA" head.
 
Agree, build the 360. The 308 casting cyl. heads work well. Some port work, cleaning and maybe mill them some...A good goal would be 9.8 to 10.0 for street/iron heads. Not sure you need larger intake valves. If you only street drive this, you may see a more driveable combination with the 1.88" valves. As for a quick acceleration, have you ever considered a 904 with the low gear set? [2.74 vs 2.45] and the weight mass difference? I have run a 904 for many years with no problems. Good luck on your build.
 
Thanks for the advice. I will go with the 360 and clean up those 308 heads. Roller rockers, @ 1:6 and probably some pistons that will leave .005 to .008 below deck.

BTW the advice was very timely. Just blew the motor in it up. It has a very strong 318 in it now. Went to pass an old man from second gear at 3k and the thing didn't shift into third as it usually does, when I looked at the tach it was on its way back down to 6k. No smoke or oil but the distributor shaft will turn about 180*

Looks like things are looking up for me, now there is no excuse and I get to work on it at all hours of the night.
 
Yea, well, you got us early birds just at the right time, ha ha ha ha!
 
I agree, build the '91 360. The 308 heads are pretty capable with a little work, I have a set on the 340 in my Duster. I had the valves opened up to 2.02/1.60 and a stage 2 port done on them, they flow 264 cfm @ .500". You can definitely get more flow with aftermarket heads, but you can still make a lot of power flowing 264 cfm. The only thing is that if you're paying someone to do the porting and machine work, it may actually be cheaper to buy the aftermarket heads. If you're doing most of the work yourself, the 308's are a great way to go.
 
I would do the 360.it's a Hydo roller already so you just need to pick a good cam and you seem to have the shortblock sorted out.
 
Yea I will try my hand at porting. Cant do the valve change though, myself that is. May even bore it .040, get forged pistons and put a 100 shot on it.

I figure no need for the money on a 4" crank (when I can put it into the heads) when I'm looking to leave folks scratching their heads and wondering what I just hit em with when I down shift into the 2500-3000 rpm range and flat out blast off.

So its a 360 bored .040, roller cam with, good heads with some work. Good roller rockers@ 1:6. Aftermarket forged pistons to put me at close to zero deck and in the 10:1 compression area with 68-72cc open chambers. And a 100 shot at wide open throttle.

Guess I better throw in a good aluminum radiator and electric fans too. Also a 800cfm carb of some reputable make, rpm air gap dual plane intake with a 1" spacer?

I don't know but I have a feeling these boys in their pony cars are fixin to get schooled by a nearly 50 year old pony car. I guess the Barracuda was one of the first pony cars.

Thanks again guys, yall sure know your mopars.
 
walk all over new mustangs and camaros with basically a stock headed, stock stroke 360??
I guess the shot of nitrous will help.
Why bore it out so much also? the less the better....unless you're gonna map out the wall thickness (sonic check) and will bore in a cnc...
If you're buying new pistons anyway, stroke the thing.
 
Oh I didn't realize a .040 over was too much. May as well stroke it, your right. Seeing as how every one suggested building the 360 I will just go that route and search the board for some 400-450hp builds and then put a 100 shot on that. Glad I asked cause I was under the impression that having a target rpm range of 2500 -3000 rpms at about 35-50mph as a starting point I would have been better of with some sort of high rpm destroked engine with nitrous.

Thanks again
 
Stroking pretty much any engine adds anywhere from $1200-2500 to the build. There are at least dozens of folks on here running quick 360s. There's no specific "need" for a 408. Build the engine well, set up your light little Barracuda correctly, and you'll have little trouble keeping up with, or walking away from potential competitors...until you run out of gear. Pretty sure you can build up a 425-450 horse 360 capable of fun times...but I agree more with rumble...suspension and chassis are where the real improvements lie...having power isn't worth jack dammit if you can't put it to the ground.
 
*I think* I just found my new sig line!

It's true, in the street, a 360 can run low 11's and be a 10 sec track car. But like Tex said
".having power isn't worth jack dammit if you can't put it to the ground." And that will be your issue. Building the engine power to what you want is the easy part.
 
That's the way I see it too. I feel like extra money on a crank would be a waist for my purpose. Heads probably not so much. I certainly don't want to be constantly breaking traction which is why I was asking about a build that would launch hard while going down the road already. Which, again, is why I mentioned a de-stroked motor on nitrous. Seemed like there wouldn't be a traction problem at say 3000rpm and up and it would get to the peak power rpm range quick.

But I trust you guys and I'm hearing keep it simple and the power from a bored out 360 with worked 308's or even after market heads with a great valve train will do the trick just fine,

Suspension on car is great. Lowered, front and rear sway bars, heavy duty rear springs and good shocks, disk brakes on front. Has no body roll that I can tell. Feels like a go cart. A whole lot better than the Charger patrol car I once had, at least in cornering.

Never tried to launch it hard cause I just didn't care to break something. It has no subframe connectors.

So I take it 425-450 HP is about what I would need before I have to start tweaking the suspension and tires. I'm guessing the Barracuda weighs about 3300lbs.

Thanks again.

BTW if those 308 heads have a crack between the intake and exhaust valves and I could get my hands on some W2's with shaft mounted roller rockers that have been milled and ported with 2.02's in them would they work on the later model LA. Seems like they do have the bores in the block for LA type oiling but wouldn't I need a different push rod length.
 
Yes the W2 will work on all LA engines. How the rockers get oil is up to you. Via pushrod or through block into head oiling. Pushrod length? Probably so but check anyway. A lot has to do with what W2 you have. And what gear it has.

You could have traction issues with a 300hp engine. Need put a label on it so quickly. Everything has a limit. You may even find your good parts not good enough for a upgrade in HP. It's easy to break tires loose on most anything. If I can do it on a late model 180 hp 318 in a Duster with 3.21 gears.........everything stock.... Minus wide tires and rims...

Beef up the chassis with frame connectors and such. There's a big differance in how things change. 1 change at a time.
 
What he said-traction is king in racing just like shot placement is king in hunting. You said the car is like a go cart, and that's cool, but if the suspension angles, shock and spring rates aren't optimized for thorough transfer of power, you can and will lose traction. Unfortunately, I'm not well-versed in correct suspension setup...but there are probably a few folks on here who could help you out quite well.
 
Rumblefish360, what do you mean by "A lot has to do with what W2 you have. And what gear it has". Specifically what gear it has. Are you talking about the car? It has 31spline axles 8 3/4 with Yukon 373 suregrip.

There is a place in Durham NC that makes the connectors. I think they are about $320 bucks for a set. Been eyeballing them for a while.
 
If you really consider W2 heads, price out rocker set up first. Those are really pricey unless you can find used set.
 
There is a long valve version of the W2 where it uses a taller valve springs for greater lifts. Then the rocker gear and how and where it sits in the saddles.
Once everything is sorted out, then you'll need to check everything over again and see what you may need. Like longer pushrods.
 
The heads are the long valves. They have everything on them already. Harland, rockers, springs valves ect. Guy on this forum has or had them for sale.
 
rumblefish360 said:
The cars *** coming out from under you and getting in front of you is a suspension traction issue. Not a HP/torque issue.

My advice is build the 1991 "LA" roller block and upgrade the heads later. Ported 308's are fine. And since your doing that work, cheap! Building a Magnum engine limits your heads to Magnum only heads. The problem is the lack of a block oil passage for the more common "LA" head.
Click to expand...

This!!¡!!!!!!!!!! Absolutely, the best common sense thread,I've seen in along time. Chassis & drive train ,first. This gives you, a stable tuning point. I agree with the 360,no stroker crank needed. GOOD MACHINE WORK(read actually accurate...) ,a matched cam/compression/airflow/gear combo, it's a relevant deal.
In re edit : The whole thread,has so much to offer,I picked his.(I like picking on him,lol) Chassis & suspension, first. That's where the basis starts.
 
Up date on build for the 66 cuda. 408 stroker offset connecting rod to reduce side load,
Bullit roller cam 236/245 @ 50, 110 sep. 106 degree, 574 lift

W2 heads, offset roller rockers 1.5 with 208 intake 165 exhaust, shaved to get 9.5 compression. Ported and polished

PTC 9" convertor with 4500 stall

Holley dp built to flow 950cfm

Hedman fenderwell headers step tube.

front and rear sway bar, subframe connectors

ss springs with spring re location

and the widest tire I can fit on it. hopefully that will fix most of the jack dammit traction!

Engine is almost finished. I'll let you guys know how it works out.
 
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