what the max horsepower that a built 4.3 put out..i was told so many numbers 250-400. 250 seems low and 400 seems way to generous for a v6. do you need a v8 trany for a 4.3?

 

Fisrt of all... Yes you will need a v-8 tranny to run the 4.3 it is basically a 350 with the last two cylinders chopped off. It will bolt in just like any small block v-8 and as for horse power for the 4.3s 400 hp is a good target number if you really push the limits you can make 450 reliable ponies but it wont be cheap

Best of luck to you and personally i would try to build your 4.3 to about 300 to 320 hp thats all you will ever need