Big block open chamber heads

[Mark #28455]

Re: Big block open chamber heads

The original 427 GM pistons did hit. In about 1970 or 71, GM changed to a new forging that was straight across the pin boss and those no longer hit.

[Mark #28455]

30 year old technology

What's the point in having a sports car you can't run at WOT? If you're going through all the trouble to rebuild and the pistons cost about the same, why not get the right compression? You don't actually lose any significant power because you can restore the original full timing advance. Remember the old crate LS6 10.3:1 motors? They could only run 32 to 34 degrees advance because of knocking on pump gas. GM went to 9:1 on the new 454 and 502 so you could run full advance and guess what - the horsepower on the dyno didn't change! It's much more fun to be able to drive with no hassles and to be able to outrun a mustang or two without having the car pinging away.
Just my 2 cents.