I have a 1978 camaro with a 305 v8. It has a 4160 Holley quadrajet.I had it timed at 6 degrees before and always backfired out of the carb. Then i changed it to 4 degrees before and i can accelerate it when its in park but not in gear.My timing is perfect and my distributor advance is brand new. i think it is my tranny and its bogging down my engine.

 

Do you have another carb to try out on it? I had a backfire prob once and it was my carb.

 

Its either a rich or lean condition. Probably lean. First, is it a q jet or a holley? Pretty sure 4160 is a vac secondary 600. Most important lets get the primary settings on the carb right. Get your float level set first. It should be right at the bottom of the sight plug and when you rock the car it spills a little. This should be done idling on flat ground. Then unplug the vac advance and plug the line, then hook a vac gauge to manifold vac. (the port under the bowl) tune the idle mixture screws for best vac and make sure there turned out even. Probably 2-2 1/2 turns. Then plug your advance back into the ported vac on the side of the metering block. Then set your idle. About 600-800.

Take it for a spin. You might want to put it back to 6 degrees. I'm not sure. Assuming the centrifugal weights are working right you should have 28 degrees in the dizzy plus the initial = 32*-34* total timing. There are a ton of other things that can be done but see where your at and get back to us. Welcome aboard.

I'm sure someone else will chim in with some other good tips too. The point is don't make more than one change at a time so you know if your going in the right direction.

 

It is a quadrajet 4160 Holley with an electric choke. i did tuned the carb and got it to stop backfiring as much but when i parked it in my shop my engine overheated and my water pump blew out and water shot out of my valve covers, intake manifold everywhere.

 

??? Can you elaborate on that one?

 

LOL thanks for askin the question. And a pic please.

 

When it overheated water came out of the bolts holding my valve covers. and sadly i don't have a camera

 

Water came out of your valve cover bolts? Those shouldn't even be tapped to a water passage.

 

I wonder if he means the intake manifest?