silentvoice19

I was wondering to make a 393 its just a bigger crank with stock rod length right?? BTW this is on a 351w of course.....I was also lookin into nitrous also on the motor...maby a 200 shot.Either that or i was gonna leave it the stock 351 and pump a bigger shot into it.Thanks guys

uedlose

393 is yes a crank change and 351W rods with 302 pistons in a 351W block

silentvoice19

What are the differences between 302 pistons and 351w pistons??? their the same bore size right??

LX 90

im thinking its the compresion height, but dont quote me on that

silentvoice19

hmm i wonder if it would lower my compression........using a 302 piston

uedlose

bore is the same but like said the compression height is diff.

silentvoice19

well how diff is the compression height??? are the 302 pistons taller or shorter than the 351w pistons. this is a 75 block BTW

woodsy

a std 302 piston compression height is 1.600 and a windsors is 1.772

silentvoice19

hmm ok so it would be small how much would this affect compression??? say with a 63cc head and a flat top piston sayin it will yeild a 9:5.1 with a 63cc head.Im tryin to figure my ball park range i have a goal for compression with the nitrous.

woodsy

If your planning on pump gas a flat top in a 393 will not work. Going to have to be a dish in the area of 15-20cc's. Figuring 0 deck, .041 gasket with a 4.100 bore, 4.030 bore, 63cc head, and about .230-.250 first ring land depth.