Greetings all,

Before proceeding through Sofa’s Holley tuning sticky,
what jets, PV, accel pump cam would be a decent starting point on this 1988 IROC Z?
For right now, it’s a bone stock long block TBI L03 305 T5 3:08 with Hooker 2055’s, Hooker Aerochamber 3 inch exhaust, with the monster 179*/194* @ .050” TBI cam and those #187 swirly heads.

The intake would be a Performer Vortec, a Mallory 4309 pres reg, & and of course a non-computer HEI.

Planned Holley is a #4776 600 DP pri/sec jets are 69/71’s, with a 6.5 PV. The prime mover will eventually be a carb’d L31 350.
Thank you.

 

Start with the carb's out-of-the-box setup; it should be very close for your engine. Evaluate how the car runs, and then go from there.

 

If you haven't bought the carb already, you might want to consider spending a few more dollars ($642) on the Quick Fuel SS-Series SS-650-AN carb - it would be worth the upgrade IMHO (annular boosters, clear sight plugs, electric choke, billet metering blocks, etc).
https://www.holley.com/products/fuel...arts/SS-650-AN

The annular discharge boosters should provide better off idle response compared to the standard 600 DP. Plus the baseplate for the 650 is the same size as the 750 - meaning you could buy a 750 main body later if you wanted more performance from the 350.

 

Ironwill & BadSS,
Thank you both for the wise advice.
Unfortunately I already have the #4776 Holley.
Had a QFT VS 750 made prior to the Holley/QuickFuel buy-out on another vehicle, and loved the response those annular discharge boosters gave.
A stock 305 TBI IROC is such a poseur I know lol....except maybe for freeway cloverleafs.
I’ll just put the 600 on & take it from there until the real L31 goes in.
thanks again.

 

I'm trying to do the TPI to carb swap and everywhere on here says get the Mallory 4309 fuel regulator but I can' find it anywhere. Is there like a holley regulator that would work or where did you find yours to buy?

 

Mallory went under. You need a 3 port FPT with a return.