I was trying to set the timing on a buddies SBC 350. To get it running I had to set it at almost 90 deg. on the tab. I think at some point this motor had a newer balancer, IE one that you look through the water pump, and I am trying to read it on the 40 deg tab. How would the motor act if this were the case?

Spud

 

The bolt-on tab is about 30-35° behind the weld-on type.... so if you took the late balancer and set it to "look" right on the early style tab, it would be roughly 30-35° retarded from where it belongs.

The motor would run very very lazy, if at all; produce very little power, and generally act sluggish, and unwilling to increase RPMs; overheat; turn the exhaust system cherry red, from combustion still being in progress when the exhaust valve opens; and drink gas shamelessly.

 

I timmed it by ear, but it still doesn't rev real well, And it does drink more fuel then it should.

 

Sounds to me like you should abandon the marks, and simply adjust it to where the engine runs right, which is what you're really interested in anyway. The engine itself doesn't look at the marks in order to decide whether the timing is optimum, so neither should you.

I'd suggest starting by advancing it until the engine pings under heavy load, and back it off until it just stops pinging, and go from there. That'll get you pretty close to perfect even if you just leave it like that.

 

Thats what I did, Maybe I just turned it back slightly too far.