CoolDansta

Okay so I have an 87 Z28 that was originally a 305 but previous owner put a 350 In it with the valve cover bolts on the center as opposed to the edges. The car has a QUadrajet but the car lags when I rev it installed a Holley dual feed carb and runs good but I wanted to know if I have to do anything to the transmission or anything else in general since its electronic, the QUadrajet has plugs connected to it that's why I'm asking. please help!

CoolDansta

Or do I have to do anything with the distributor? It has two plugs going into the back and the coil is separate it's not one that mounts on top of the distributor the coil has two plugs

RedLeader289

iTrader: (2)

Did you replace the Qjet with an electronically controlled Holley? If so then you should be fine. If you went with a non-computer controlled carb then you'll need to make some changes.

Sounds like the PO swapped in a newer 350.

CoolDansta

No it's a regular mechanical carb Holley I have a fuel regulator on it. Do I need to change distributor as well?

RedLeader289

iTrader: (2)

Ok, well there's two ways you can go- Wire the Q-jet up correctly and get it working.

Or

Verify that you have, or swap for, an HEI distributor with vacuum advance and tune everything up.

there are benefits for both ways, depends on how much prior knowledge you have of the car, i.e. did the PO rip the computer out? is the current wiring a total hack job? etc.

midias

I would probably just tune the Qjet but if you insist on keeping the holley or the wiring is screwed up then you need a new HEI with vac advance and the tq converter will not lock up properly if it is an auto but you did not say what trans you have

Ozz1967

iTrader: (4)

I'd wire the Qjet back up.

With the holley to run properly, you will need a vacuum advance distributor and a lockup kit for your transmission or you will burn it up.

MSgt Luttrell

I agree he will need a vacuum advance distributor, but the lock up kit is optional; I would suggest a lock up kit if he is interested in peak gas mileage, but I know lots of people that run a 700R4 with out a lock up torque converter. Even a lock up converter with out the lock up will work just fine, gas mileage will suffer some but it won't burn up the transmission. He will also have to make sure that the Holley Carb has the correct linkage installed for the 700R4.

five7kid

iTrader: (14)

Assuming it is a factory automatic transmission:
If you don't utilize the torque converter lockup, then you need to modify the transmission to operate without it. If you don't, it will build up excess heat - which may not exhibit itself right away, but it is hurting the transmission. The 3-4 clutch pack is the typical victim, and it may seem fine in "normal" driving. But eventually it will fail without proper modifications.

Also, the TV cable connection to the carb is very important. It's best to get a "geometry corrector" bracket to bolt to the Holley throttle arm so the transmission gets the proper information about throttle position. It's much more than the old "kick-down cable".