This will sound silly but a real wolf in sheeps clothing is the chevy 307! yes yes yes they are weak stock but..... They are basicly a 283 with a 327 crank they rev very fast because of the short stroke and come with flat top pistons but!! the heads and cam are were all the performance is lost! they have the smallest valves i've ever seen in a SBC head and massive combustion chambers. I bought a 307 for $50 a few years ago and put it in my 66 chevy shortbed and it wouldn't get out of its own way. Swapped out the heads for 882 305 heads with the smaller combustion chambers and big valves stuck an edelbrock performer intake on it a performer cam and a carter AFB on top. It would SCREAM! the 350 that had the same intake/cam/carb setup before would not even touch the power that the 307 had it would rev fast and rev high and held together very well. It didnt have the low-end tourque of the 350 but man it would get up and go.