5.4

[Mercracer]

Originally Posted by boosted331

Are you kidding me? A sportsman 302 block is BARELY stronger than a late model thin wall casting, and is basically identical to an early model high nickel block. With a 4.6 you need some 600 dollar rods and 600 dollar pistons, and your bottom end is solid to 1000+ horsepower. To have a 302 motor that will take 1000+ horsepower you need 1500+ for a block, 800 for a crank, 600 for some rods, 600 for some pistons. For the 4.6 swap all you need is a new ECU, swap k-member, and some ingenuity. The cost of the swap is easily taken care of just by the price of buying a good block (Dart, R302, World) not even including machine work. Keep in mind a bare R302 needs quite a bit more machine work than a preused 4.6 block to get it ready to run.

You are way off base comparing a 302 Sportsman block to a Mexican block. NOT basically identical. The Sportsman block will go hundreds of horsepower more. To say that it is BARELY stronger than a 5.0 block is a great exageration.
I was actually referring to the 351W Sportsman block. Real world drag race performance, the A351/A5.8 blocks will live in the 800-1000HP range.
Even if you use factory ignition and fuel management (even with a flashed ECU) as it appears you are advocating with a 4.6, it commonly runs 3500+ for a complete donor Cobra motor with harness, etc. That is before you put your rods and pistons into it, and before you adapt it to your car.
The bottom line is that relatively few people are going to build a 1000HP motor. This thread is about someone wanting to do a budget build. Most people asking about a first time build have neither the resources nor experience that you or I have. Therefore, a 4.6 or 5.4 swap is not the best means to their end.