400 flywheel hp N/A in a streetable 302 with a stock bottom end on a limited budget, with a 150 shot on top of that? I might be off base here, but I do not think you have set a reasonable goal. The 185's would only be a start. You need to be looking at building a high compression stroker motor with a custom cam. A pro engine bilder can give you the blueprint you need to reach the power goals you want. I hate to see you spend money on the motor, then be dissapointed when you are not making the power you expect.

Bolting AFR185's onto a freshened bottom end is going to yield marginal results. I would think the loss of torque would be more noticable than the gain in horsepower.

If your budget is low, look for some 6037's or GT40's, a Performer intake, punch the block 30 over and get it set up for 11.5/1 or 12.5/1 compression. You would need new pistons (forged) and then build a balanced motor. Then a custom cam, and you would be happy. I would think a setup like that would see in the neighborhood of 300 - 320 flywheel hp. Of course, you need the fuel system to keep up - 30 lb injectors, 190lph pump, adjustable fp regulator, and go larger on the intake side as well.

Of course, I could be completely wrong. If that is the case, ignore everything I just said and I will go back to sleep.