Which head offers best performance for the 70 LT1

[Bruce N.]

I'm building a LT1 motor for my Corvette and interested in feedback on which may be the better performing head. 414 - 492 - 186 - 041 ? Any help would be greatly appreciated. Thanks Bruce Noland

[Chas Kingston]

Re: Which head offers best performance for the 70

I ran the stock 186 heads on my '70 LT-1 and was quite pleased. Some would recommend porting and polishing, with gasket matching on both the heads and the intake, with a three-angle valve-job, for better breathing.

[Joe L.]

Re: Which head offers best performance for the 70

Bruce-----

All of the cylinder heads you mentioned will provide just about equal performance. From a performance perspective, their design specs are so close that, for all practical purposes, there is no difference.

For an original configuration cylinder head, you're pretty much limited to these heads, too. However, keep in mind that while these are good cylinder heads, they are 30 year old technology. From a performance perspective, modern aluminum cylinder heads, especially those manufactured by AFR and Edelbrock, are the way to go.

[Bruce N.]

Re: Which head offers best performance for the 70

Thanks for helping out guys. I race NHRA stock eliminator and must use a stock version of one of the above mentioned numbers. I have used the 492 head before but have no experience with the other numbers. We are always looking for something just a weeee bit better. Thanks again. Bruce

[Mark #28455]

Test individual heads on the flow bench

My engine builder works on a lot of "stock" dirt track cars. He flow bench tests every individual head prior to using it in any of his engines. If you're looking for every last HP you need a stack of about 20 heads and you'll notice some heads have one or two really bad ports even in heads with the same casting numbers - core shift.

Good luck,
Mark