Q-jet setup (w/ mild cam)?

[jared stewart]

I have a '79 350 in a '81 1/2 ton 4x4 automatic
My question is what is (or how do I figure out) the best combination of jets/rods for my Quadrajet. This is just going to be used for a "work/play" truck buy I'd like it to have plenty of power when I want it, but try to keep my mileage fairly reasonable.
Here's the specs I have on my motor:

300 HORSE DOUBLE-HUMP HEADS W/ 202 VALVES
HEADERS
ALUMINUM HOLLEY INTAKE (Contender)
DOUBLE ROLLER TIMING CHAIN SET
HIGH OUTPUT COIL
STANDARD BORE
STANDARD PISTONS

COMP CAM 12-239-3
12-239-3 CS X4 262H-11
Lobe separation 111°
Gross valve lift 0.462" Intake @ 0.05
Gross valve lift 0.48" Exhaust @ 0.05
GOOD LOW AND MID RANGE, EXCELLENT RESPONSE, NOTICEABLE IDLE
RPM OPERATING RANGE 1300-5600

Thanks for any help guys.

[Grim Reaper]

Pick up a book by Doug Rowe called Rochester tunning.

There is no use "X rodX Jet and X cranks of the mixture screw" formula. Doug goes over how to read the spark plugs and figure it out. There is so many variable. Elevation, compression ratio, Amount of Vac the engine pulls, ambiant Air temp etc.

You probably won't need to do much. There is a good chance that you will be happy with the performance. If thats a reman carb I have noticed they are a little fat on the mixture with the jets out of the box. The sweet thing with a Quad is the do a lot of adjusting themselves. As long as it's inital set up was correct you can usualy take a Quad off a 305 and stick it on a 350 and do next to nothing and have it run good.

[jared stewart]

Thanks Grim,
It's not a reman, I'm in the process of rebuilding it and thought while I had it apart I'd see if anybody had about the same setup and had rejetted it with success. My main problem right now is that the secondary rod cam is broke and I can't find where to buy them. I'll probably just leave it as is for now.
Thanks again.

[Grim Reaper]

Originally posted by jared stewart
Thanks Grim,
It's not a reman, I'm in the process of rebuilding it and thought while I had it apart I'd see if anybody had about the same setup and had rejetted it with success. My main problem right now is that the secondary rod cam is broke and I can't find where to buy them. I'll probably just leave it as is for now.
Thanks again.

Oyyy!

I have a spare carb for this reason. It's starting to get hard to find parts. Might check with Eddlebrock. I think they hold the pattents and all the tooling now.