Hello All,

I am in the middle of a 393 stroker build. I have a 3.85" Scat crank and I am using Speed Pro .030 over pistons. I installed the first 2 pistons and found that when rotating the crank the counterweights on the crank just touch the bottom of the piston skirts at the bottom of the stroke. I was first using 302 pistons and thought I messed up, but now I just purchased 351 pistons and the problem still exists. Any help is greatly appreciated as I am running out of patience.

Thanks in advance..

 

You have a 3.85 crank, 6.2 rods, with 302 pistons. I have read this is the formula for a 393. You may have to do some notching on the piston skirts, are you using stock 302compression height pistons?

 

The 351 pistons are almost certainly wrong for this application. I believe this crank is to be used with the stock 351W rods (5.956" long) and stock type 302 pistons.

What part number are the 302 pistons you have?

What connecting rods are you using?

 

2X stock 351 truck rods are the best. I have a set I will trade ya for the 6.200's or I could trade ya my 3.75 Eagle stroker crank for your 3.85 crank. It is made for 6.200 rods.
& I do not have any 6.200 rods yet...

Lookin for some if anyone has some. I beams will do