Cammed up 283's ( and cammed up 305's for that matter) don't have a lot of low end torque.
So you need a stiff rear gear ratio and a higher stall converter to make em go.
A cammed up 283 needs a 3000++stall.... a typical "3500 stall" 10" converter will only realize about a 3000
stall when behind a 283CID motor.
A 283 with a big cam and a low compression ratio "stock" will be a dog.
A cammed 283 needs a 10:1cr a 3000++ stall (3500 stall rating 10" converter) and 4.10's or its not going to be even in the program. all the power is up higher in the rpm range.
305's are not much diffeerent. when you cam them up, they need compression, gears and a generous stall speed.
typical stall rating of typical converter will show about 500rpm less stall behind a 305.
So don;t be shy when selecting converter stall speed.
If you are not willing to do that, change the camshaft. very easy to over cam a 283 and a 305.
A cam like the comp 280H magnum (280 230@.050" .480" lift) needs 4.10+++ gears and a 3500-4000 ++ real stall 9" converter and 10:1cr in a 283-305 cid motor. The taller the tires and-or the heavier the vehicle, the more gear it will need.
If you're not gong to gear it up, don't use a big cam.
The stock HEI distributor advance curve will not work well on a 283 with a cam. It needs to be modified with a advance curve that suits the cam and purpose.
More detail if you ID the cam in the motor.
Last edited by F-BIRD'88; 11-11-2012 at 08:51 PM.