I am sticking with the stock rims 15" 6 lugs, sm420 and the 3:90 rear diff.
Which stall converter would make the most sense?
How reasonably tall a tire can I get on stock rims?
What diameter exhaust is the best size?
Anyone know if corvette larger exhaust manifolds will work on an apache or are there better ones?
I can answer some of this for you.
No need to worry about what toque converter to use, that's for automatic transmissions (it would come into play with a 350/350 combo, though). With the SM420, all you need is properly adjusted clutch and pressure plate.
On tires, the stock wheels are going to limit you on size. 215/75/15 is about the largest modern tire that will work on them safely, they're right at about 27.7" tall on average, which is pretty close to the OEM 6.70-15. Anything larger will lead to foul handling due to lack of sidewall support.
I would think that 2" would be sufficient for a 283, or even a mild 350. Especially if you're running duals. For the manifolds, look for the rams Horn manifolds, they're probably one of the best factory designs, and were used on virtually all of the Power Pak and Fuellie cars.
