Heads and Intake

[Garys1969RR]

Just got a great deal on a 68 Valiant A Body ready to race, with extra heads and 2 intakes. Can anyone tell me what heads these are? Mopar P/N 4532134. Heart shaped combustion chambers. Intakes I think are the M-1s. P/N 4532250 and 4532251. Also, the engine is supposed to be a 496, but it is a 383 block. Must be a 383 stroked to what, 4.15" ? Any thoughts/ideas? And I would be willing to sell one of these intakes if anyone needs one. Like new! Thanks

 

[max340]

Just got a great deal on a 68 Valiant A Body ready to race, with extra heads and 2 intakes. Can anyone tell me what heads these are? Mopar P/N 4532134. Heart shaped combustion chambers. Intakes I think are the M-1s. P/N 4532250 and 4532251. Also, the engine is supposed to be a 496, but it is a 383 block. Must be a 383 stroked to what, 4.15" ? Any thoughts/ideas? And I would be willing to sell one of these intakes if anyone needs one. Like new! Thanks

I found this, hope it helps. http://board.moparts.org/ubbthreads/ubbthreads.php/ubb/showflat/Number/5240324/site_id/1#import

 

[Garys1969RR]

OK, I think that must be the casting number. P4532134. It IS the number cast into the head itself. I'm thinking these are Stage 6 heads? Anybody know? And they do appear to have been CNC ported. Anyone know what head this is for sure? Heart shaped combustion chambers. Mopar cast into the end of the head.

 

[Garys1969RR]

I found this, hope it helps. http://board.moparts.org/ubbthreads/ubbthreads.php/ubb/showflat/Number/5240324/site_id/1#import

Thanks! Yes, that's helpful. Too bad the Stage 6 heads need so much work to perform well. I found that a 383 block with a 4.25" stroke results in a 496! I think that's with a .030 overbore.

 

[Garys1969RR]

Anyone have pics of the Stage 6 Mopar heads?

 

[lewtot184]

the stage 6 is a raised port alum head designed for use on the low deck engines. they can be used on RB engines with intake spacers. they use an RB intake on a low deck. chamber's are around 75 cc. they do need port work. there are some porosity issues with some of them. i think the real issue is how much money your willing to throw at them. i think they have a niche, but from a race stand point they are somewhat obsolete. the edelbrock victors took the stage 6 idea to a higher level.

 

[Garys1969RR]

Thanks lewtot! They came with 2 head to manifold spacers, so I think that's what they are. And they appear to have been ported. Judging by the regular and precise grind marks, I think they were CNC ported. The Stage 6 heads have the heart shaped combustion chambers, correct?

 

[lewtot184]

Thanks lewtot! They came with 2 head to manifold spacers, so I think that's what they are. And they appear to have been ported. Judging by the regular and precise grind marks, I think they were CNC ported. The Stage 6 heads have the heart shaped combustion chambers, correct?

they do have a heart shaped chamber. i would caution about "over" porting the heads. i don't think they are reliable 300+cfm heads (of course the disclaimer here is the happy flow benches,..lol).

 

[Garys1969RR]

Hard to believe that Ma Mopar would build an alum head for the aftermarket that didn't have such great flow, but I have heard this before. Some guys claim good power output with these. I realize they came out in the 90s, and the technology has progressed alot since then. I don't think the 496 that's in the car has the Stage 6 heads, as it has a low deck M 1 on a 383 block.

 

[lewtot184]

i think those heads would be at their best between 430-470 cubes. the ones that i'm familiar with flowed high 270's after some home port work. eventually a professional porter got a hold of them and ruined them trying to get big numbers. after doing some port work they're about on par with edelbrocks. one just has to keep mind that when they came out the only alternative was the indy dash ones. i still think there's a niche for them. i wouldn't use them on an RB engine due to the raised exhaust port and the added cost of finding headers to fit. a low deck with a light weight bottom end, cam/intake to match the heads, and a light weight a-body would be fun.

 

[rumblefish360]

At the moment, I can't remember whom it was MoPar had doing the CNC work on the Stage VI heads, (Cuapman?) but besides the crazy price for them, they did flow into the mid and upper 300cfm range. Standard and max wedge port sizes.

I agree with a cube limitation for best results. How ever, putting them something larger would change the focus of the build. The engine would be better at big torque production than big HP.

Current head offerings are cheaper and flow better with higher quality. It is very hard to ignore this. Use of this head falls into a category I call, "Build it with them because you WANT to build it with them." Kind of like a "Retro day 2 build or Nostalgia build."

For small block guys it would be a W2 or W5 headed engine. Edelbrock RPM ported or Victor heads have taken there place at a inexpensive price level by compare.

If you didn't already have the Stage VI heads on hand, I would never recommend them to be purchased for use. There are so many big block head choices out there today. The expensive MoPar head is last on the list.

 

[Garys1969RR]

Thanks for all your replies, I am a little more knowledgeable on these now. I'll post some pics of the porting once I get my computer to accept them from my phone.

 

[lewtot184]

i dug up some flow numbers. see if i can post them later.

 

[lewtot184]

flow numbers from heads i'm familiar with.
home ported: intake exhaust
.1-68 .1-61
.2-128 .2-119
.3-189 .3-165
.4-237 .4-205
.5-268 .5-224
.6-280 .6-233

professional: intake exhaust
.1-79 .1-57
.2-161 .2-123
.3-224 .3-164
.4-265 .4-205
.5-290 .5-230
.6-294 .6-241
.7-300 .7-243

the flow sheet doesn't state it but i believe the exhaust numbers are with a tube. the pro work ended with holes in the heads under the spring pockets. i think trying for 300+ cfm on these heads is a crap shoot.

 

[lewtot184]

ray barton numbers; intake only: .1-76
.2-151
.3-214
.4-257
.5-275
.6-279
.7-283

i believe that both sets of numbers i've posted are realistic; not some inflated pie in the sky crap to get someone to buy something.