I am rebuilding a 67 camaro . I have installed a 350 chvy crate motor and a 4 speed automatic trans. Headers , Dual Exhaust Flowmasters. I am not trying for a race car, just a good performer.
The car runs fine except it is getting 10 mpg (terrible economy) and stumbles on acelleration in 4th gear.
It seems worse when the engine is cold, and it takes a while to warm up.
I have replaced the Holly carb that the engine came with , with an eledbrock preformer and nothing changed. I have tried changing the advance, adjusting the carb. What next?