Smitty275

ProComp Aluminum Cylinder Heads Bare Castings. $795/pr. + $65 S&H READY TO SHIP
Will fit 330/350/403/400/425/455 and D/DX 350.

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Options/add ons:
Assembled w/77cc chambers, Stainless Ebrock Valves, springs for flat tappet hydraulic cam, etc. $1595
Ported & Assembeled $2295 2.072/1.680 FLO 300/180 70cc CHAMBERS
Ported & Asssembled $3177 2.150/1.650 FLO 340/210 CHAMBERS PER REQUEST FROM 70cc-55cc, CUSTOM MANLEY VALVES, HYD ROLLER SPRINGS.

cellblock dee

exactly how do you get those heads to flow those numbers do you have a CNC program ?

Smitty275

As far as getting the heads to flow it is initially all done by hand a little at a time. Back and forth from work bench to flow bench. Then templates are made so it is easy to reproduce each port. After doing a pair ir two of a given head I can usually get very close before I even pick up the templates. Since the ProComp castings are new I do not use a CNC. Though it would make reproduction essiey it would add expense due to the low volume of heads ran. Should demand grow I'll have the ports digitized and go that route. Each head is guaranteed to produce the numbers on the included flow bench test sheet that accompanies each head. I've had my own flow bench for about 20yrs and have never had a customer that took heads for independent testing come back with numbers less than I tested at.

cellblock dee

I already have a pair a pro Comp heads how much to get them to flo 300 and 180?and also what do these blow out of the box and at what lift will they flo 300 ?what is the most horsepower /torque you've gotten with these heads ?

Smitty275

On your castings its $1595 for 300/180 @ .600 w/70cc chambers.

As far as with these heads I have not had opportunity to do any builds shooting for max power. But if you build it right and maximize your combination 650-700hp is well within reach.

Ces

Nice. Very respectable ! I'm currently sourcing parts for a 1970 W-30 engine build. Since the correct F heads seem too expensive, I'm considering alternatives. I'm going to add this to my potential parts list. Thank you

real57vetteguy

I sent my heads to Smitty late last year. I was OVERLY happy with the results and I did have them put on a local flow bench. They flowed within 1-2 cfm from what Smitty stated they flowed. Very honest and great work. There are a lot of big names out there claiming 300-320 cfm @ .600 that really flow 270-280 cfm and they charge more. This is the real deal!

cellblock dee

real57vetteguy

We are still putting mine together. 468 bottom end. Edelbrock air gap and heads done by Smitty, pro systems carb, ARH headers. 480lE trans with paddle shift. But this isn't helping Smitty's original post...sorry for side tracking.

cellblock dee

I was asking because I've never seen anyone with a build to tell me how much horsepower they were getting out of them ?

Smitty275

There are a lot of things that influence HP. "IF" the engine is built in a manor to make full use of the cylinder heads potential you can figure on approximately 2.3HP per CFM of intake flow as your max HP potential. And yes that should ring true for these heads as well as most others.

Even on engines that are not meant to make absolute maximum HP better flowing heads will make more power. Remember an engine is nothing more than an air pump and, to an extent, the more air in the more power out.

camshaw

are you flowing them at 28" of water on the column or 26" or 30" ?

Smitty275

I use the accepted industry standard if 28".

camshaw

ok thanks. some guys dont. do u have the low and mid lift numbers? i know procomp has a mixed reputation but how many sets of these olds heads have you sold? the chevy boys ive spoke with either say they hate there chevy heads or they love them! lol. they raised the exhaust ports and added longer valves so u cant run standard bolts etc. any changes with their olds designs? thanks. sorry for all the ?s. cam

Smitty275

I only use the ProComp castings that come machined with seats and bronze guides. All other hardware I supply from trusted sources like Manley, Milodon, Edelbrock, etc. depending on the build.
Yes, I have all the numbers. Just not off top of my head. Below is a thread that is mainly about the ProComp head from a while back. There are some flow numbers and a lot more pictures for you to peruse.
https://classicoldsmobile.com/forums/showthread.php?t=74468

Smitty275

And yes, the early ProComp heads for the Chevies were suspect. No denying that. But they have grown a lot since then and continually improved. Their castings for all of their heads are very good now. I know of several shops who use their SBC and BBC castings just as I do and out fit them to fit the build. Then they put their own insignia on them.

friscoplayrsf

Would these heads fit a olds 403 CI? How high would the compression ratio be?

Smitty275

Yes, they are a direct bolt on. Compression ratio can be from stock to "more than it should be". I can cut the chambers to what you need which is what would determine the cr based on piston used.

Ces

This is awesome! These are sounding better and better ...
I'm paying full attention.

Ces

Btw, Smitty, are the heads and prices you listed in this OP for Olds 455?
Let me know, thx!

Smitty275

330/350/403/400/425/455 and D/DX350

Ces

Cool tx

cellblock dee

I've got the olds pro comp heads ported and polished I want to put bigger intake valves can you tell me who has the biggest ones that will fit in here and what dimensions they are?

Smitty275

I can only refer you back to the person who performed the work on your heads.

cellblock dee

if I use 2.150 in /1.650 exhaust valves will i have to use a shaft mount rocker system or will everything still lineup w/ hs 5016 rockers?thanks for your help

Smitty275

A lot to this question. Why run lash caps? Which Manley valves? (I'm a warehouse distributor for them.) Are they off the shelf or custom?
Alignment, pushrod/stud/valve/rocker isn't going to change. But where the roller ends up on the valve tip may. ( Centered vs inboard/outboard.)

cellblock dee

At what lift are these heads flowing 340 ? And what is the max lift and springs are you using ?

Smitty275

Fully ported with chamber work I have them going 340+ @ .600 lift. Max lift can be anything within the realm of lobe size and rocker ratio and has to be known going into the build so proper components are used. With regular roller rockers you limited to about .800. With shaft mount over an inch is possible.
I use custom Manley valves. Springs depend on application (cam type). Usually Manley, PAC, or CC.