im willing to bet you could do a gen III 5.3 or 6.0 for far less than 8k.Long story short, I've not had the summer I was expecting and that has left me recently with free time to think about what kind of engine I want for my Camaro when I get around to it (I'm beginning to feel like this will end up like the latest installment of Duke Nukem and be forever in the planning stage). I've came down to two engine choices, with value per dollar spent being paramount. I will keep the emission's system for 50-state legality, so that means keeping TBI.
Rebuild & do some machining on the all iron 305, work on the TBI & ECM, clean up the heads with some porting & new Manley valves, a relatively "hot" (by 305 standards) XR264 cam from COMP, and Hooker Super Comp Shorty Headers & Cat back with a Magnaflow cat. Keeps me emissions legal and generates, according to Desktop Dyno (not scientific, but good for getting an idea), 291 FWHP & 335 FWTQ. Cost: $6200 once you figure in machine shop time and some other items.
Drop in a GMPP Fast Burn 385 (GM Performance 12496769 - GM Performance ZZ4 350 C.I.D. 385 HP Engine Assemblies - Overview - SummitRacing.com) and transplant the rest from the 305 build list. DD reports 340 FWHP & 378 FWTQ. Cost: $8700
The 385 gets me a 350 platform which is far more versatile than the 305, and its all aluminum top side seriously cuts down on weight (which for me & AX/RR is great). The drawback is that I could build the 305 to the same levels for more headache & almost the same money and yet be stuck with a setup that wouldn't be worth putting on a 350.
Any emissions legal, weight saving engine suggestions would be welcome. $8k is the limit (with good exceptions allowed but not more than $1k over 8) I'm placing on an SBC and $7k (same overrun as the SBC) on an LSx and that includes everything from the radiator to the exhaust tips. If I could find L98 heads from an 87-91 Corvette, that'd be great for the 305 but those don't pop up but once in a great while. I'm not as up on LSx swaps, but a stock LS1/LS6 would be perfect if it could be installed and be emissions legal.
6.0 - 1000
t56 - 1500
custom harness 1000
motor mounts 85
x member 100
so thats not even 5k, im sure there are more odds and ends, but nothing major, and you could add a cam in there and make 400 to the tires!!! i know its not a drop in deal like the others, but ill tell you, it is a better choice.