who runs 13sec to 12.80 in the 1/4

DusterBoy15 said

piston tops look like this

http://www.raceindustry.com/ART/products/lgthumbnail2704_5.4modford.jpg

Click to expand...

Those look like mid 70's era 360 pistons. Compression between 7.8-8.5. You will need to upgrade pistons and increase compression to 9+ if you want to run low 13's-high 12's.