are scj 429 pistons the same as 429 pistons . i am building a 429 and the pistons i got are 40 over flat top scj forged , i know my motor is 10.5 cr stock with dove heads will these pistons change this

 

Eye brows I think.so don't quote me

I once read that:

There are single eyebrow pistons (CJ/SCJ application)
double eyebrow pistons reg 429
Canyon style pistons (racetrack cutout) on newer 460's
Flat top no eyebrow piston

 

What is the brand and part # of your pistons????

 

speed pro dont have part number rite now

 

If your part # for your pistons is L2366, then you have the CJ/SCJ pistons. I built a 429 using these several years ago.

 

just wondering the difference btween 429 reg ,cj ,&scj i bhave 429 scj piston (speed pro40 over) they are flat tops with one valve releif . i am wondering what they will do to com ratio with my dove-c heads.or maybe i cant even use them in a reg 429 block, i hope i can they cost me a fortune

 

I used those same pistons when I built a 429 years ago and I used DOVE-C heads with CJ valves installed. They worked fine. I just so happened to have the original 429 piston from that motor laying handy and checked it. It had 2 valve releifs and was cast, C8VE casting number. Just my guess that the 2nd valve relief bumped the compression down .5 point. As far as the pistons working with the block, the answer is yes! Finding pump gas to burn with 11:1 compression on any engine is another story.