Sb/bb?
Man there are going to be many opinions on this!
But a stroker 360 is the best all around bang or the buck, less weight, will drive good on the street and handle good. But if you use the better stroker parts like forged crank etc. you will still have 6-7k in the engine, then you need to figure out which trans and type, there is another $1k-$2k+ convertor.
Rear end, well and 8 3/4 I would think is in the car will take either SB or BB on the street just may need gears posi unit etc re-worked. Also go with a larger drive shaft and large u-jointsgood investment.
On the big block you will be OK too but I would do stiffing plates and heaver T bars up front, which you may want on a SB too.
Also what about brakes on the car to stop this thing? minimum early A 4 piston front disk and 10" rear drums or go with a 73-76 A body setup for sure if it is a BB! They are heavier and the upper arms and ball joints are stonger too. But you mentioned tubular so I guess Wilwood brakes???
Either way they both run great and I know a few guys that have BB cars that handle and stot great too.
Well thats about $20k work of stuff if you do it up 500-600HP and al lthe bes parts, radiator etc...
A factory 340 back to bone stock would be great if it is to be a numbers matching car BIG $$$s!
Take your time, plan it out by the time you want to take to complete and how much you want to invest in money in the car!
PS I would do a stroker 360 for the street much easier few less $$$..
:rock: