I'm looking to change carbs on my 87 firebird 305. And I've heard that converting from the ecu controlled qjet to a no ecu carb is bad on the car. And i know you can do carb to tbi conversion which doesn't use the stock ecu. So my question is how do I swap out carbs for a little more without messing anything up? Can I just unhook and remove the ecu and wiring without doing any damage. Or is there another way around it? And doing so will it clean up all the hideous vaccuum lines covering the engine?

 

The non ecu carb swap will not hurt anything. You just need to do it right.

You must replace the carb of course but also the distributor. You have to use the older style non ecu controlled HEI large cap distributor.

If your car is an auto transmission you will need a torque converter lockup switch kit as well

 

It's the 5 speed. So that's all I'd need to do is carb and distributor? What do you mean older style? Like gen 2? Or can I find it by looking up large cap HEI distributor?

 

Older style HEI as in not computer controlled, but with vacuum and mechanical advance. You can use an old factory unit, or buy a new one.

If you have a factory intake manifold, the square-bore type carbs like Holley or Edelbrock won't bolt to it without an adapter, or replace the intake with an aftermarket type that will take a square-bore carb.

If you put a non-computer q-jet on it, it will bolt to a factory intake manifold.

Since you have a T5, a Holley-type double pumper carb would be better than a q-jet or Edelbrock or vacuum secondary carb.

 

That was the plan. Holley 650 carb. With edlebrock dual plane performer intake and just a mild cam. Maybe do heads down the road.

 

When you swap the distributor, use the factory power and tach plugs, and you are good. You won't need the third plug.

 

'87 had the small-cap, divorced coil distributor. It doesn't connect like the large cap, coil-in-cap HEI.

But it isn't hard to adapt the '87 power wire and tach signal to the older style large cap HEI.