273 / 318 Exhaust Manifold Question

OK the 3.23 gears in the 8 3/4 are a good snappy gear set for running around town, yet still get up to speed out on the highways. So that's good.

Single plane intakes are not real good on low end torque, dual planes are better for low end.

Here is the thing with your 273 and heads. Intake manifold bolts go in at a different angle than the newer aluminum intakes and newer 318 heads.. Then you have port runner size most of them large port. So then you get a miss match at your head ports.

Your single plane is port matched to your heads now and bolts up properly. So I would think I would stay with your factory port matched single plane for the smooth port flow that is already established with those parts.

The LD4B intakes are perfect for the 318s but the bolt hole angles are off for the 273.

Maybe a little carburetor Increase would give you a little more fuel or just re-jet it. And some different Springs in the distributor to help the timing to come on sooner may help too.

Still running a points distributor? Those are fine, just want the points clean and set right.

Do you have mechanical valve train, if so that needs to be adjusted again, that can give you a power boost.