Replacement heads on Stocker - Page 2

SDT1DYI · 03-06-2019, 10:29 AM

It is curious how NHRA tech dept approves a replacement cylinder head when the runner volumes are considerable larger than their own stated specification. Its been said replacement heads are worth 15-20 HP on a SBC combination. The replacement heads with the HP penalty, seem to produce the same ETs.

Steve Teeter. STK. 6380

Alan Nyhus · 03-06-2019, 11:03 AM

Quote:

Originally Posted by SDT1DYI

It is curious how NHRA tech dept approves a replacement cylinder head when the runner volumes are considerable larger than their own stated specification. Steve Teeter. STK. 6380

A good example is the Edelbrock NHRA accepted head for small block Chevy Stockers.

- OEM head: 165 cc intake/65 cc exhaust
- NHRA specs on Edelbrock heads (5 hp penalty) : 172 cc intake/65 cc exhaust
- Edelbrock's specs on these heads: 185 cc intake/65 cc exhaust

When I asked an NHRA Technical official about this, I was told (paraphrasing) that if anyone showed up in Stock with the accepted Edelbrock heads, they would be illegal if they had the 185 cc intake ports. And if the intake ports measured 172 cc, they wouldn't pass because they would have to have been illegally modified (welding) to get down to 172 cc.

Coleydog · 03-06-2019, 04:50 PM

I think I heard that phrase before, we'll pass it to see what's in it.
Mike

bubski · 03-06-2019, 07:22 PM

So !! a set of closed chamber iron heads is more expensive than a new set of aluminum heads ?? Whats next ?? the cam is hard to grind with the stock lift ??

RULER · 03-07-2019, 03:13 AM

This replacement head deal is way out of hand, there are plenty of good stock casting for SBC and oval port and square port BBC, you just have to get your wallet out and there really not that expensive when your building a competitive stock or super stock Engine, And no you can't buy them from jegs or summit.

Terry Cain · 03-07-2019, 10:45 AM

Quote:

Originally Posted by bubski

So !! a set of closed chamber iron heads is more expensive than a new set of aluminum heads ??

Yep

HP HUNTER · 03-10-2019, 10:27 AM

Quote:

Originally Posted by Terry Cain

Does anyone think that shortly/soon NHRA will open up and allow after market heads in stock. Some of these heads are getting very hard to find and also very expensive.

I have all the factory oval port heads and some of the rectangle port cores cleaned and magged virgin ready to go at fair prices.

206
702
215
063
290
292
802
049
781
236

Adger Smith · 03-11-2019, 09:54 AM

I have a few singles left in my core storage.
PM me and if I have what you need I will get back to you.

03-06-2019, 10:29 AM	#1
SDT1DYI Member Join Date: Nov 2016 Location: Indianola Washington Posts: 407 Likes: 0 Liked 456 Times in 148 Posts	Re: Replacement heads on Stocker It is curious how NHRA tech dept approves a replacement cylinder head when the runner volumes are considerable larger than their own stated specification. Its been said replacement heads are worth 15-20 HP on a SBC combination. The replacement heads with the HP penalty, seem to produce the same ETs. Steve Teeter. STK. 6380

03-06-2019, 04:50 PM	#3
Coleydog Senior Member Join Date: Jul 2014 Posts: 572 Likes: 39 Liked 53 Times in 38 Posts	Re: Replacement heads on Stocker I think I heard that phrase before, we'll pass it to see what's in it. Mike

03-06-2019, 07:22 PM	#4
bubski Member Join Date: Dec 2009 Posts: 228 Likes: 14 Liked 165 Times in 60 Posts	Re: Replacement heads on Stocker So !! a set of closed chamber iron heads is more expensive than a new set of aluminum heads ?? Whats next ?? the cam is hard to grind with the stock lift ??

03-07-2019, 03:13 AM	#5
RULER Member Join Date: Jan 2006 Posts: 222 Likes: 15 Liked 58 Times in 18 Posts	Re: Replacement heads on Stocker This replacement head deal is way out of hand, there are plenty of good stock casting for SBC and oval port and square port BBC, you just have to get your wallet out and there really not that expensive when your building a competitive stock or super stock Engine, And no you can't buy them from jegs or summit.

03-11-2019, 09:54 AM	#8
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: Replacement heads on Stocker I have a few singles left in my core storage. PM me and if I have what you need I will get back to you. __________________ Adger Smith (Former SS)