The 283 will respond to a nice port job on those heads just like any other SBC.
Get the heads up to around 235cfm from stock 197-200cfm and you will see a whole different motor.
Thats not a huge port. 170 ish finished port volume.
A huge difference. 283's need head flow too.
And most of the gains wil be at high valve lift, where a higher valve lift will pay off. .500" net lift
Keep the intake duration short for spunky street torque and acceleration.
The SBC ZZ4 crate motor cam with a 1.6 intake rocker arm is ideal for this ... 208-221@.050" 112LSA .505" in .510" ex.
Use the new beehive OEM GM LS6 springs with a comp 787-16 spring retainer 1.6-1.5 rocker set.
2.02 valves in this head require the chamber to be opened up. Definaly the wrong direction when trying to get compression on a 283.
stay with 1.94x 1.50 or 1.55" valve. Port the heads to wake up the head flow. Improved flow with plenty of port velocity.
Keep the chamber small.
Last edited by F-BIRD'88; 01-13-2013 at 09:18 AM.