Ok first off ...long time reader. First time poster..
Engine is 396 sbc. 11.4.1 compression. Callies crank. Callies rods. Probe forged pistons.. afr 190c.c. heads .rpm air gap manifold. Comp xr288hr cam. 1.6 pro magnum rockers. Holley 750 dp.. Hei disty with msd rev module. External msd coil. Need any more info just ask.

In a 1990 c1500. ..
Has a tko 5-speed. And 14 bolt corporate read-end with 4.11 gear and auburn locker.

so I have a wideband Afr gauge in my exhaust from zeitronix.

At WOT truck runs great. Pulls hard every gear. Afr of 12.9 to 13.1 ..

But wile cruising and anything under 3000rpm. It will buck and sputter and wanna miss some. It feels. Afr stays steady at 13.8 to 14.5 wile cruising. Timing is 16* int.. And 38* at 3k.

I have to almost stay in 2nd or 3rd gear and keep rpm at 3500.. To make it run smooth? Ideas and help. Thanks. -Curt

 

Have you checked your tps and iac??

 

do not have them . it's carbed. 750 holley dp

 

damn for some reason i though it said tbi..... In that case do you have a vacuum leak anywhere? Base gasket maybe?