Old pro stock heads

October 28, 2024, 07:56 PM

67Duece

Old pro stock heads

I just came across a set of old pontiac heads for a BBC and i was wondering if they would be any good for a bracket car and they have the rocker arm systems with them, Is there anyone here that knows anything about them? Thanks in advance.

October 28, 2024, 09:47 PM

Alaskaracer

Compared to todays heads, they are way behind in performance. There are conventional heads now that will outperform them. However, they can and do run pretty well for what they are, biggest thing I'd be worried about is if they have been hurt and repaired, overheated, etc. Aluminum degrades over time and not properly taken care of, they can lose heat treat and be pretty much junk. The rockers are very likely shot, at a minimum in need of a rebuild. Unless it's a smoking deal, and you're willing to gamble on them, I'd pass if it were me. You have a 50/50 chance of getting a great deal or getting screwed. Those heads are pretty old and you don't see them too much anymore. There are some still out there running though. They will require a specific intake for those heads as well, generally going to be a sheet metal intake. There are no cast intakes I'm aware of that fit those heads, and if you have to have an intake made, stand by for a $5000 or more bill....
But after all of that, yeah, they will work on a bracket car.

October 29, 2024, 06:11 AM

183N

Most people I’ve seen buy old pro stock heads to “turn it low rpm and go bracket racing” end up not happy with the performance.

Another issue is parts availability since everything is one off.

October 29, 2024, 06:58 PM

67Duece

Honestly i got a heck of a deal on them and they came with a Intake and Pistons and rocker arms. I need to find a set of valve covers and have looked everywhere but no luck yet.

Thanks Guy's

November 03, 2024, 12:51 AM

BP758

I think you be surprised at the results. Go for it! We’ve been running old pro stock heads for years!

November 03, 2024, 09:05 AM

wideopen231

I would think if you are going to spin the motor some they will; work great. If running mid 7k probably ok just not optimized. JMO

Now being lover of high rpm if you happen to have a set of old mopar Hemi bolt pattern heads off pro stock. Send them down I will test them for you.

November 03, 2024, 09:25 AM

BP758

Chris, We don’t spin ours 9, 10 or 11k. Cam it right and the heads follow. We chose to run DRCE parts because they are readily available and the platform is solid. Better than conventional . Our sponsor took care of us.
It’s like running a Brad in TD! Nothing better..

November 03, 2024, 09:52 AM

TD3550

quote:
Originally posted by 67Duece:
Honestly i got a heck of a deal on them and they came with a Intake and Pistons and rocker arms. I need to find a set of valve covers and have looked everywhere but no luck yet.

Thanks Guy's

Are those 875 Castings? (Last 3). Put a call in tomorrow. See what he has left.

November 03, 2024, 08:36 PM

67Duece

The only numbers I can find are 10045427 and they are next to the valve area on top of the head.

November 04, 2024, 08:52 AM

TD3550

it appears they take a big chief valve cover . It's an 18 degree head 427 casting

Valve cover # 12341643. I talked to him last night. He sold off everything he had with that head. Went to newer 18 degree. i looked also for VC's found nothing also. If you haven't seen or read this already as follows.
#10045427 ~ this is the SD large port pro-stock head.

#10093386 ~ [15° valve angle] (fully machined)

#10093385 ~ [15° valve angle] (RAW unfinished)

All these head no.s are intended for Mark IV blocks only.

Info on #10045427 is as follows:

Port volume = 460cc int./145cc exh.

Intake port length is equalized to within 1%.

Intake valve angle is 18°,and the exhaust is 9°.
(This is listed as a 8° "roll" over a stock BBC)

91cc combustion chambers.

Can use up to 2.40" intake & 1.90" exhaust valves.

Uses 3/4" reach gasket plugs.

Is cast from A-356-2 aluminum alloy.

The head requires longer valves,and a dedicated shaft rocker set-up,not to mention a matching intake manifold as the port location is unique.

Valve covers for these heads are #12341643

November 04, 2024, 09:15 AM

Goob

If the heads are great for 500 cubic inches at 9500 ish RPM, then you need to figure out how many more cubic inches it will take to maintain port velocity, at more reasonable (bracket friendly) RPM's.
There's always the option to epoxy the ports smaller.

No reason the heads cannot be good for your application.

November 04, 2024, 09:59 PM

BP758

quote:
Originally posted by Goob:
If the heads are great for 500 cubic inches at 9500 ish RPM, then you need to figure out how many more cubic inches it will take to maintain port velocity, at more reasonable (bracket friendly) RPM's.
There's always the option to epoxy the ports smaller.
No reason the heads cannot be good for your application.

Hey Goob!
Our 636 has drce2 heads, straight off our sponsors motors. Camed correct peak torque is 6200 999 lbs and peak power is at 8300 at 1397. At 2270# runs 6.70’s 202 plus many times. Nothing done to the heads. 49cc combustion 4.685 bore. Dished 7cc cp pistons yields lots of compression.
For years ( I mean years!) we never spun it over 8100. Didn’t need to. Now it see’s 83-8400. Yes I’ll send you dyno sheets. For us it is a solid platform with no regrets.
We sent John Marcella our head specs. He’s done things for us in the past with great results. His opinion is they will support 700 inches at 8100 plus.

November 04, 2024, 10:41 PM

B KING

^^^Excellent running combo with experienced/knowledgeable tuner(s)!

2BKING
Relaxing

November 05, 2024, 04:03 PM

FootbrakeJim

quote:
Originally posted by BP758:
Our 636 has drce2 heads, straight off our sponsors motors. Camed correct peak torque is 6200 999 lbs and peak power is at 8300 at 1397. At 2270# runs 6.70’s 202 plus many times.
For years ( I mean years!) we never spun it over 8100. Didn’t need to. Now it see’s 83-8400

Definitely a bad hombre, Barry!
Man, the idea of spinning that long stroke that high gives me the willies!

Care to share what bottom end stuff you are running? (Crank & Rod Mfr would be fine, no need to give away secrets, haha).

November 05, 2024, 05:24 PM

67Duece

quote:
Originally posted by TD3550:
it appears they take a big chief valve cover . It's an 18 degree head 427 casting

Valve cover # 12341643. I talked to him last night. He sold off everything he had with that head. Went to newer 18 degree. i looked also for VC's found nothing also. If you haven't seen or read this already as follows.

Thank you for all this info,I am just going to hang onto these for a little while and i may put them on a 565 later as i got the intake with these heads and also the rocker shaft assembly. I am not looking to set the world on fire I was just wondering if they would be okay to use in a bracket motor. Once again Thank you.
#10045427 ~ this is the SD large port pro-stock head.

#10093386 ~ [15° valve angle] (fully machined)

#10093385 ~ [15° valve angle] (RAW unfinished)

All these head no.s are intended for Mark IV blocks only.

Info on #10045427 is as follows:

Port volume = 460cc int./145cc exh.

Intake port length is equalized to within 1%.

Intake valve angle is 18°,and the exhaust is 9°.
(This is listed as a 8° "roll" over a stock BBC)

91cc combustion chambers.

Can use up to 2.40" intake & 1.90" exhaust valves.

Uses 3/4" reach gasket plugs.

Is cast from A-356-2 aluminum alloy.

The head requires longer valves,and a dedicated shaft rocker set-up,not to mention a matching intake manifold as the port location is unique.

Valve covers for these heads are #12341643

November 05, 2024, 05:30 PM

BP758

quote:
Originally posted by FootbrakeJim:
quote:
Originally posted by BP758:
Our 636 has drce2 heads, straight off our sponsors motors. Camed correct peak torque is 6200 999 lbs and peak power is at 8300 at 1397. At 2270# runs 6.70’s 202 plus many times.
For years ( I mean years!) we never spun it over 8100. Didn’t need to. Now it see’s 83-8400

Definitely a bad hombre, Barry!
Man, the idea of spinning that long stroke that high gives me the willies!
Care to share what bottom end stuff you are running? (Crank & Rod Mfr would be fine, no need to give away secrets, haha).

Hi Jim!!
CN billet 4.900 block, winberg 4.625?/ 4.685 CP, Carrillo steel rods.bullet cam 287/314 118.5
83-8400 is nothing for this combo, that’s why it lasts.
Zack Baker / Stan Justus carbs. 2.300.

November 05, 2024, 05:31 PM

BP758

Jim
We’ve been running that combo and a 650 for the last 13 or more years..
Just freshened the 650 three weeks ago with new carbs. Found 16 foot lbs, probably 18 hp or more and it picked up vacume too.
We have a baseline pull 5800 to 7500. All gains show up without pulling to peak..8300.
Can’t wait to bolt those carbs on the 637.

This message has been edited. Last edited by: BP758,

November 08, 2024, 05:34 PM

BJs Wild Ride

We had a 584 with 427s that had been worked over pretty good. They had Almost qualified for pro stock once or twice. T

The 584 was on one medium kit. When the chambers fell out of the 427s, they were replaced with a worked on set of 18 degrees. Car picked up .01 to 60’, lost 1 mph, and ran the exact same ET.