1987 b2000 v8 swap

need to know if i have to cut or modify anything for a v8 swap in my truck.(fender wells,firewall etc...) it still runs fine with 240,000 miles and no smoke on original motor but i want more power.

That would depend alot on which v8 you are refering to. If you are planning to swap in a Ford 427 SOHC you will have to do alot of cutting, however if your plans include an Oldsmobile 215 I doubt that any cutting will be needed.:evillol: