I finally have started driving my Z28 around. Took it for the inaugural cruise last night.

First off... it runs Very strong.

The 75 jets are however very lean, it surges badly while cruising, then starts to trail off. I'm thinking of going right to 80's and trying it there for a bit.

Second it's still got the stock pump cam in it. It's gotta go, it's got a huge dead spot off idle at any but low throttle settings. What cams should i start off dicking with.

I think the timing is about right, or close enough, base is 16* it's all in at 3000-3200

about the car
350, 10.65 compression, xe274 cam, vortec heads, rpm intake& 1" spacer. 3.73 gears, 700R with a 9.5" 3300 stall act converter.

suggestions?

 

What carb?Try a dark green pump cam and 35-37 shooter.

 

LOL Doh yeah i forgot the carb didn't I

It's a 3130 holley. 780 cfm vac sec with downlegger boosters.
as for the squirter i've got a 35 in it now. hell it barely ran with the original 21 in it.

sounds like it's time to pick the pump cam assortment up

 

First off never change jets 5 sizes at once. Stick to 2..you'd be surprised how easy it is to overcompensate and drive yourself nuts.

Don't judge jet size by what it does while cruising either. Use your A/F gauge, and get them right at WOT.

I doubt you need any bigger than a 35....that might even be too much. Play with all the cams...see which gives you the best results. Be sure to readjust the pump arm lash between each change.

 

As far as the jets go..I agree with Jester on only going two sizes at a time.Five jet sizes is a HUGE increase in fuel.Now a question for Jester??On my Speed Demon 750DP I am currently running a 42 squirter with orange pump cam from the Holley kit.Jetting is at stock Demon spec of 76/83,power valve is a 9.5" as per Demon instruction of using one that is about 2" below manifold vacuum of 11.5-12" at idle.This seems extremely large of a squirter to me.Same XE274 cam as Pony Killer..but with AFR 195's..initial timing set at 22 degrees..total of 36 by 3,000 rpm along with a Weiand Stealth.I got rid of the dead spot off idle but it is still lazy on the initial rev when idling.No one seems to know why I need to run such a large squirter??

 

I dunno why you'd need to run such a large squirter either. Maybe Demon sizes them differently..I'm not really sure about that. But hey..if it works..it works. if i still has that flat spot then change to a smaller size, and experiment with different cams.