GT40 heads and rocker question??

[a1yola]

I am planning on installing some GT40 heads onto my car. The block is stock and it has a very mild cam (unknown specs) still using the stock heads and rockers.

My question is:
Can I install the GT40 heads and use the stock (non GT40) rockers from my stock heads? I am assuming that they will work since I have no problems with them on the stock heads, with the current cam, but I want to make sure.

Also, if I were to use some 1.6 or 1.7 roller rockers, will it be safe since I do not know the specs on the cam? Thanks.

 

[Jack's95gt]

That's no problem using the stock rockers on the GT40 heads. They still use the same pedistal mounts for the rockers.

 

[a1yola]

would you know the performance difference if I used aftermarket 1.6 roller rockers opposed to the stockers?

 

[dstang01]

would you know the performance difference if I used aftermarket 1.6 roller rockers opposed to the stockers?

old thread i know, but Im looking for the same answer

 

[NIKwoaC]

There was JUST a thread on this like 2 days ago.

Stock rockers are non roller, stamped, and sloppy. The 1.6 RRs are more efficient, produce less friction and heat, and are more accurate because of their higher stiffness being a solid piece rather than stamped. However, 1.6 ratio is equivalent to the stock ratio, so there is no real flow advantage in them. Some sources say the stock rockers can flex and produce less than 1.6 ratio. Of this I’m not sure.

This being said, the most improvement I’ve seen in a dyno test using 1.7 RRs (larger than stock, therefore making more valve lift) over stock is less than 10HP gain.