Truck manifolds on Dart Sport?

My 70 Dart, had 2 1/8 right side 92 Magnum RT manifold and driver's side 69 340 manifold. No problems

When I discovered that I was leaving 20:hp on the table vs headers I got Doug's D453's.

Had to raise the driver's 1/2 inch with washers to clear ps box, clearance is very tight between the box and the coupler. I was concerned that the additional heat would damage the ps box,.

I removed the tie rod ends, steering box arm, and center link as I was also rebuilding the front suspension, which made header installation easier.

Quality control was poor on our A bodies. The same set up in another 70 could be a 1/4 to a 1/2 inch difference plus or minus.

Dougs and TTI do not have the center link passing thru them when installed versus other cheaper headers. I had heard and read that many have bought inferior headers
That hung TOO LOW and we're easily smashed and dinged.

I ordered a new manual box with fast 16.1 ratio, a Borgeson universal joint for the steering column rod. Zero problems anticipated, many here have done the same thing with excellent results.