hey..... i just blew up my motor last friday and i got another one but i was thinking of doing the 4.5 stroker.i got most of the parts to do it like the crank and rods but i was reading where alot of people put a new intake manifold on older 4.0's? i have a 4.o high output and i understand it gives you a little more horse but do i have to use that or can i use the old one?also anyone who has done this is it alot more power or should i just build a 4.7 and not waste my time with the 4.5?

You don't need to change the intake. I have built many many strokers over the years...both old and new style, light and heavy cranks, etc etc. Power difference, sure...small. Worth the work? Depends on you.

The difference between a 4.5 and a 4.7 is only how much you bore the block. You won't be able to do 4.5 unless you are starting with a new block that is the stock bore. 4.6 is most common, .030 over bore.