Piston ID

Reply Subscribe

Thread Tools

Search this Thread

Nov 16, 2001 | 09:20 PM

Unibody

Thread Starter

New User

Joined: Nov 2001

Posts: 8

Likes: 0

From: Tulsa USA

Piston ID

Help I'm trying to ID some pistons, the only casting number I can find is B711 on the inside of the skirt. These pistons are installed in my .30 over 391. The picture in the book by Steve Christ on page 37 upper right corner is what the tops look like. But..in the August issue of Street Rodder on page 175 upper right corner item #4 says 428PI. I'm using C6AE rods and C8AE-H heads. I'm trying to figure the comp. ratio.
Also, do you guys understand the cranks numbers in the Christ book when it states from (service. Q80,001 truck). Its greek to me.

Nov 18, 2001 | 12:09 PM

dinosaurfan

Cargo Master

Joined: Aug 2000

Posts: 2,931

Likes: 12

From: SW Michigan

Piston ID

[updated:LAST EDITED ON 18-Nov-01 AT 01:11 PM (EST)] UnibodyPhil, I have both of those publications but can't put my finger on either one of them right now. Is the piston you are looking dished or flattopped ? Most 390s came from the factory with dished pistons, there are regular fuel (big) and 4V or premium fuel (small) dished pistons out there. Many 390s in mid 70s trucks came with leftover 410 Mercury pistons to give lower compression. There are lots of 390s in service that guys have rebuilt using 360 flat tops, to give 9.5 or 9.6 to 1 compression. If you are going to do any towing or plowing, the dished pistons can give 8 or 8 1/2 to 1 to let you do it on regular gasoline. What are you going to ask this engine to do for you ? DF

Nov 18, 2001 | 03:41 PM

Unibody

Thread Starter

New User

Joined: Nov 2001

Posts: 8

Likes: 0

From: Tulsa USA

Piston ID

These pistons are dished with eyebrows and they sure look like factory pistons. Have in my street truck with RPM, 600 and Lunati cam. Been running what passes as ethel these days with 14 Static advance and no pinging. Christ book says I should be around 9:5.1 but I'd rather be sure.