XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Seems to me the easy thing to do would be to get a K-member out of a slant 6 car, and you'd probably be "home free."
A slant 6 is somewhat lighter than a V8, and that will improve the balance of the car. You'lll enjoy easier steering, which will be appreciated, since you're going "non-assisted."
I'd like to take this opportunity to congartulate you on your clear-headed thinking regarding your decision to go with a boosted /6.
The advantages are many, but you probably already are aware of that, since nobody's having to talk you into this. For the street, particularly, I feel it's a smart choice. The turbo /6s LIKE rear axle ratios in the 2's, with a 2.76 working really well for some pretty fast drag /6 cars. That means ONE rear gear for both the drag strip and the highway. THAT means, you are not married to an expensive 8.75" A body rear end; an 8.25" out of any junkyard Volare or Aspen (or Duster/Demon) will be a bolt in... for a LOT less money than the requisite drop-out 8.75 that will fit your A-body.
A modified (welded-on turbo flange) stock /6 exhaust manifold will be a LOT cheaper than a set of TTI headers (for a normally-aspirated V8,) and the engine will likely be quiet enough as to not even NEED a muffler... more money saved.
Turbo engines (at east street-friendly versions) like cams with minimal duration, much like a stock cam, so driveability and fuel economy is excellent; radical cams in V8's that make good power, don't usually have a very good idle, and low end torque is in short supply. Around-town driveability suffers... as does fuel economy.
A stock torque converter is usually a good match for the flat torque curve of a turbo /6; hi-po, radical-cammed V8s need more stall speed, to make use of their high rpm potential. More money saved...
The useful (performance) rpm spread of a turbo'd /6, pretty much seems to end about 5,500 rpm, so the 7,200 rpm stresses that the hi-po V8s see, just aren't there. RPM's are an engine killer, not cylinder pressure....
Building a turbo /6 isn't cheap. It can be FAIRLY cheap, if you want to forego the detonation protection that forged pistons and rods afford you, but if you choose to run stock (cast) pistons, you'll be limiting yourself to boost that is in the less-than-10-pound range, if you want your engine to live a long, healthy life... That will give you a high 13-second car, which isn't slow, by any means. My advice is to rob a liquor store (just kidding) or take a second job for long ehough to be able to afford a set of Wiseco forged pistons and K-1 forged rods, and sleep secure in the knowledge that you now have at least, a modicum of detonation protection.
That will also give you the option of running 15-20 pounds of boost, once you get things sorted out. Boost is addictive...
If this is just going to be a fun "street" car, the forged stuff probably isn't necessary... but, is nice if you can swing it. Ditto, the intercooler.
Expenses will be:
a properly-sized turbo
a properly-sized waste gate
cold side plumbing
an intercooler
a water/meth injector
a blowoff valve
a cam (although a stock cam works pretty good...)
a blow-thru carb (modified circuits for boost)
a new fuel system (3/8")
electric fuel pump
boost-oriented pressure regulator
Modified distributor advance curve
Boost gauge
I said it woudn't be cheap... and, it's not, but neither is a well-built small block V8 that would keep up with this boosted /6....
You pays your money and you takes your choice...:cheers:
Hope this helps...