have just swapped my cc carbed LG4 for a reconditioned 350 using the same carb and dizzy. Would Hypertech's chip 11191 (chev caprice 350 4bbl auto) work for me? Anywhere else I can go to get a suitable chip?

Thanks for your help

 

I'd expect the Hypertech chip would likely be a waste of money.

How's it run now, with your old LG4 chip?

Keep in mind that the CCC ECM really only controls timing, TCC, idle fuel, and some emissions functions. It has only limited control of the carb via the idle mixture solenoid, so for the most part, fuel is still done the old fashoned way.

Doug Roe's book on Q-jets is highly recommended.

I'd recommend you find the best ignition timing, by moving the distributor, tune the fuel, and see how things work.

Might consider the chip and ECM combo that GM uses with the ZZ4 HO Camaro package, although be aware that's intended for an aluminum head engine, so it will likely have more timing than what an iron head engine needs, if it were to be set at the recommended 10° BTDC base.

Since your '83 doesn't have a knock sensor, you need to be very careful to avoid detonation. '84-up LG4s had an ESC circuit, that wouldn't be difficult to add, BTW.

Matter of fact, we had a somewhat related discussion going a few weeks ago:
https://www.thirdgen.org/techbb2/sho...hreadid=229829

 

The timing curves are my main concern. The car is running ok and I have enough miles on it now to give it a bootfull. It definitely has more urge than the 305 did but I think I am used to the difference already!

The mech who put the motor in for me is going to dyno tune it and is in favour of ditching the dizzy for an ordinary hei as he is sure he can get considerably better performance than it has now - until it's on the dyno I won't know for sure.

Since the dyno tune is going to cost $200 I would like to have the timing issue reolved first.

I'll check out that thread - thanks for your help

 

Get the ZZZ engine retrofit manual, and in there they tell what ecm, knock module, and chip to run. Then get a set of decondary rods out of a 4.1L Buick. They're the only ones readily available that are close to the AVs. The CPs and AH are close enough.

Then yes Doug Roes Book.

All the dyno will let you do is select which of the secondary metering rod hangers to use, and if you don't have a set, you need to read Roes Book, and make up a set of at 6.

The mechanical dissy is a waste of time. You can't manipulate the timing as well as an ecm.

For the effort to get the CCC CORRECT, you could install TBI, and be having alot more fun. BTDT.

 

Cheers Grumpy.