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How much bolt on HP, if any, would the ProComp aluminum heads give me. Fresh 468 Olds in my 67 Olds Cutlass, fresh C castings (new valves, Competition springs, no porting, believed never cut), torker intake, headers (1 3/4 or 1 7/8, can't remember), roller rockers, and Lunati VooDoo (227/233 @ .050" & .523/.523 lift).Pistons are the Sealed Power forged 18cc dish. Wallace racing calculator says 9.54:1 static if heads are uncut, 10:1 if heads were cut .022 in their life. I'm also running a mildly built 200R4 w/3.55 gears. Car runs very nice. Would the very affordable ProComps (or even Edelbrocks) give me any bolt on HP? The Wise racing heads out of NC are the ultimate for sure but $5k is more than I want to part with, much as I know they are 400cfm heads (impressive!). What will these $1100 ProComps get me with my setup? Anything? HP estimates as is?
Last edited by Chris6542; October 26th, 2019 at 01:20 AM.
You don't say if your "fresh" C heads are large (2.07) or small (2.00) intake valves. Also you don't say about your goals for your car, race, street, etc. If your fresh heads are large valved you'll have little hp gain but a 70 lbs weight savings. You may be able to run medium grade gas with the aluminium heads. The advantage of Pro Comps is mainly in the cost of new aluminum heads vs rebuilding tired factory iron heads with new guides, valves, seats, etc =$$$$. One can easily put more $$ into factory iron heads than the cost of new aluminum. In your case (IMO) "Love the one your with". BTW, a Edelbrock Performer would, imo, be a better choice for a street car over the Torker but not worth the "change out" for now. Also Wise heads=race only in my opinion. $5k is a lot of $$ and you'd have to up grade everything, Stay away fromthat rat hole unless you want to go full race car, jmo.
The Procomp's head casting quality is good. Supposedly the valves and springs that come with heads are far from ideal, stems read all over the place and the spring rates aren't what they are supposed to be. It is a better idea to buy bare and assemble them with the springs to match your cam and quality valves. Plus you gain no compression, they actually measure 83 to 84cc, not the 77cc advertised, according to people who work on these heads.
Out of the box Procomps aren’t great. As mentioned the chambers are 80+ and the intake entry needs work.
If you clean up the entry and cut em to 77cc I’d say a 25-30hp gain would be realistic. I offer them in various stages.
Edelbrocks on the other hand are fine right out of the box. I believe a gain of 40+ wouldn’t be an unrealistic expectation.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,722
I had a set of Pro Comp/Speedmaster heads in my shop yesterday, the intake valve guides were lose, the exhaust guides were destroyed. Of course the guide OD was a odd ball size, called Speedmaster and got right through, they wanted 100.00 for their sub standard parts (guides) so my dilemma was do I spend 150.00 on custom made quality CHE guides that you can machine to size or buy the 100.00 china man junk you can't machine to size. 40 HP gain with Edelbrocks sounds right to me, of course the valve job would have to be gone through if you want them right.
Last edited by VORTECPRO; October 26th, 2019 at 05:02 AM.
Out of the box, no gain hp wise. I'm assuming your "c"s are large valve already as rebuilding small c's wouldn't make a lot of sense. The savings in weight is something to consider IMO. I bought bare speedmasters and hardware was installed and supplied by Mike Stark CFM. This was through a 3rd party local guy. At that time, IF I had known Mark Remmel -- cutlassfi I would have done business with him. Absolutely nothing bad to say about Mike Stark, he is a legend and a gentleman as well, but I don't believe he specializes in speedmaster or Oldsmobile.
Tell Mark what you need and stand by your mailbox...
Thanks to all for this great Input. First, I'm in CA with our mediocre 91 octane fuel. Second, I can see I need to have a discussion with Mark Remmel in this thread. Third, my C's are the big valve units, found them used for $300 in SF, spent about $1000 in machine work and all new hardware (SS valves, Comp springs, bronze guides, keepers/locks, SS seats). I figured my motor is around 430hp perhaps, but always think about Joe's 504hp 455 build write up online, not much different than my motor with a few changes I have to say the Edelbrocks potentially adding 25 to 40hp, esp with a bigger cam, is intriguiing. Bang for the buck is what I'm all about. Thank to all for the terrific input.
What do you want to do with the car? Race? Just chasing some extra HP?
Don’t even think about the Wise option. I’ve heard they’re not obtainable from anywhere and there’s no car actually running them. May as well try and find Bulldogs.
Sounds like your C’s are done well...if you want an upgrade, you’ll need a guy like Mark or someone else to sell you a good package.
-pete
A month after this thread in Nov 09
, I bought a set and had them flowed at my speed shop here in LA. Mark had already told me what to expect, so the results were expected. My observations and the observations of my shop that disassembled them: nice casting of aluminum, exhaust flow better than my Cs, springs were very respectable (like 135/330 if i recall), overall a very nice value. The chambers Cc'ed out to 82/83, not the claimed 80 (though can be safely cut alot). The main downside was the intake flow, not even as good as Cs. Mark told me they are a "starting point" and he was right. But aside of porting needs on the intake side, they are a very respectable product. Definitely not substandard like many think.
Last edited by Chris6542; April 24th, 2020 at 01:47 AM.
Joe Mondello ported a set of 'C's and that was the starting point for the Edelbrocks. I recall two Car craft articles where Joe built 455s.. First article was with his ported 'C's and the second article was with new Edelbrocks. Maybe a couple years later. The HP results were similar.
October 26th, 2019, 01:10 AM
