I am still fighting my loss of low end torque after I swapped in my 770 S/A for my TBI. I am running a Performer RPM vortec heads with a LT4 cam. Would a 1 inch spacer cause this loss. The car runs too good to be any problems and I have timing set a 12* with the correct advance.



Brian Felts

 

It could be alot of things all related to tuning. You say you have 12 degrees base..what is it total? When does it come in? Where do you have the vacuum advance hooked to?

Thats just ignition. The carb could have too light a secondary spring, the pump shot could be off, the primaries might be jetted wrong, or the PV could be opening too early.

Youre gonna have to go through and eliminate things one at a time with experimenting and an A/F gauge to get it dialed in right.

 

I am waiting for my timing tape to come in so I can check the advance. I am using the Proform HEI....the odd thing is that they say "performance advance curve" but I can't find anywhere to state what that is. My Ignition is also backed up with an MSD 6al. The problem is if you run it hard through the gears it is FAST however if you are in town and just want to play a little that is where is seems to lack.



Brian