sjv328

I have a freshly built olds 350 1972
bored .68 over
425 pistons
dual energy comp cam 476-508 lift
performer intake
3a rebuilt heads with springs to match cam. (I know the heads suck ran outta $$$$)
stock rear and tranny
1977 quadrajet which ran great with the 350 smog motor it had before.
question is should I keep the quadra or scrap it for something else.
its going in a 1977 cutlass supreme, and will be driving only on the weekends. I would like to get as much hp as I can. Also the cam is 275dur would anyone suggest a stall converter, comp cams says it can be used with the stock one but the motor is out so should I put a new one or not?

droldsmorland

A well tuned Quadra-Jet is hard to beat. Have it professionally setup for your application. JET offers 3 stages of builds that can be custom tuned to your spec. There are other suppliers that can tune your Q-Jet. An AVS Edelbrock is user friendly and performs well. Get the rod, jet and spring kit too. 650-750 CFMs should suffice, no larger.

sjv328

thanks for taking the time! I will look into that and because the 77 had a ton of egr vacuums and other bs. which ones can I block? the intake and motor were made without any egr equipment?

oldcutlass

I would think that most of the other BS went away with the manifold change. The Performer manifold can use a square or spread bore carb.

droldsmorland

You may want to step up to a presmogger Q-Jet carb? Say 1967-1970 spec. Generally what you need for vacuum is the brakes, the trans, the distributor and possibly other accessories like the HVAC system or vac trunk release if equipped. The brake booster if equipped, usually runs off that flare fitting on the rear of the throttle plate. The trans modulator needs full engine vacuum if its an automatic. I like full manifold vac to the vacuum advance canister. This signal can also come off the throttle plate as long as the nipple used pulls vacuum from below and not above the throttle plates. A fitting(s) in the intake can provide vacuum to all of these items. Then you can plug off everything on the carb except the choke pull off if equipped and maybe the brake booster if equipped.

sjv328

Great suggestions thanks again. From looking at the carb and a diagram it shouldn't be to hard to hook it up. Any thought on my cam and if you think ill need a higher stall

droldsmorland

Looks like a pretty healthy cam. My guess is yes along with a lower gear in the rear. Have you done your homework on valve train geometry? Olds aint a Chevy. My suggestion is to contact Competition and let their tech team guide you on proper converter and gearing assemblies. They will ask you specific questions so have all your info on hand. Ask them what your expected vacuum signal will be with this cam grind with your setup. This is a critical spec to dial in the carb. The carb shop will need this info to get your idle and off idle circuits to play nicely with the combo. The key to any build is to have each upgrade play nice with the whole system. If one thing is off it will cause all sorts of driveability problems. Once you think you have all the parts playing well together, find a chassis dyno. Thats money well spent. An hour or two on a chassis dyno will pay big dividends.
If you haven't done so already source a knowledgeable Olds engine builder regarding the valve train. This is another area where most novice builders get burned hard. And don't forget to install the dam restrictor that oils the distributor shaft at the rear of the block before the freeze plug goes in or you won't have oil pressure.
Close the loop here once you have answers to these Qs.