Hi I desperately need some advice on this. I've just swapped out the 305 for a reconditioned 350 (nothing too special) in my 83 and am using the same cc quadrajet and dizzy.

I need to know where I can get a custom or proprietary prom to suit the new motor as it is not running as strongly as it should. I can't seem to track anything down on the net, except for Hypertech who have a chip for a cc carbed 350 (pt no 11191 - 83 chev caprice, 350 4bbl auto). Would this work for me? I've tried to contact Hypertech but have not had any luck so far.

Thanks in advance.

 

The HO 350 Conversion Kit contained a PROM for the ZZ4 engine. I've heard it is still available, but I don't have the parts list print out in front of me.

The Hypertech chip should work also.

 

Thanks 57, I'll check it out.

Cheers.

 

Are you sure its the prom?

Assuming you are, the prom that you need is 24502457. (I don't know if it is still available). That's the prom used in the swap that five7kid referred to and works for the 82-84 LG4.

With that said, you might want to check out the parts list for that swap. There are a variety of other parts that go along with that swap, including a new esc and knock sensor, among others.

Check out the GM online Performance Parts catalog, or go to gmpartsdirect.com and look under crate engines.

Although I tend to prefer factory parts myself, you could have someone burn a custom prom.

 

Thanks Parrydise & 57 plus people on the prom board.

I found the parts list. For 82-84 LG4 Vin "H" it lists the following as requirements

- Controller, ECM, 1228079
- Calibrator, PROM 82-84LG4, 24502457
- Metering Rod, AH 7033812

The options for knock Sensor and ESC are not selected ie not necessary.

GM parts direct have all of these in stock, not sure if they will ship internationally though. I presume the new ecm will just hook up to the wiring harness without modification?

I would still like to know if the Hyper tech chip for the 350 Caprice would fit into my ECM as it would be a cheaper option and it's available internationally. Hypertech have not yet responded to my email though.

As I am not from the US my car isn't subject to emissions laws and has no emissions equipment fitted so I'd really like a prom that will take advantage of that, but I take on board that it is really fine tuning the secondary rods and hangar that will make the most difference.

Anyone want to make me a prom? haha :lala: