Posted on another site, looking for help

[72gs455]

Piston domes

So the 40 over pistons for my 322 show up at the shop. They don't have the same dome as stock. Will they work? Will they lower compression? Is that acceptable? I'm not building a drag racer...

Edited May 8, 2014 by 72gs455 (see edit history)

[buick man]

Well I do remember reading some years back that the replacement pistons for the 54 had a kindler and gentler dome rise as compared to the early production 53's as some of the later production 53's as I understand it, were the first to get the 54 pistons. Now maybe someone or GM still had the higher domes laying around and got installed in production on your 54 and the pistons your are looking at are the common 54 production pistons. Now I do not know if in 54 the Roadmaster's had different higher domes or not compared to that of the Super series. … just my take and food for thought.

[old-tank]

Replacement pistons are a compromise and are usually lower compression. Where did you get the pistons. Stock cranking compression on a 55 322 is 170psi and replacements from Egge are 120psi with lower domes. There is a noticeable decrease in performance. Check Mudbone restoration thread http://forums.aaca.org/f163/55-century-66r-project-292364.html he is the last one I know of that researched this.

As far as correct engine check the number.

Willie

[72gs455]

Thanks Willie,

I was at the shop yesterday and they look pretty close to the originals to the naked eye. I think the box said "Builders Choice". The shop purchased them after re-conditioning the block. It had 1 pretty badly scored cylinder and the usual wear in the others. The cylinders ended up at 40 over.