428

[1970-350]

I just acquired a 1969 428. Engine came with two sets of heads. The stock #46 heads and a set of 6X-8 heads. I’m trying to decide if I want to sell the 6X heads or install them and use them for my car. I’m not building a race car and not looking for super high HP. Just want a little more performance over and above the 350 that’s in my car now. Looking for some insight or advice. Also trying to decide between using the stock intake with my 650 4brl or the performer intake that I’m currently using on the 350 with the same 650 4brl. What’s everyone’s thoughts.

 

[melsg5]

Holley square bore, I assume that is what you have, will not fit stock spread bore intake.
Think you are better off with the high compression stock heads versus the low compression with larger valves.

 

[1970-350]

No it’s a Edelbrock Performer intake. A few guys I’ve talked to on Pontiac pages said use the #46 heads. That the 6X I would lose a lot of compression. And that I could use either the stock I take that came with the 428 or the performer I take that I currently have.

 

[melsg5]

I also said use the stock high compression heads. I see the performer is a dual pattern intake. Why would use want to use the stock cast iron manifold?