I'm fairly new to the v6's. I have a 2.8 block that I ma going to have machined and want to drop a 3.1 crank in it, is there anythign special that needs to be done or is it a direct bolt in???

 

If I am not mistaken you will need to use 3.1 pistons as the 2.8 piston's wrist pin hieght would put the top of the piston out of the bore at TDC with the 3.1 crank's stroke.

I think it's pretty straightforward other than that, just get a reman 3.1 crank from Autozone or such and use 3.1 pistons. The conrods are the same.

Our moderator and 3.1 power guru Doward will correct any misinformation I have posted, and not chastise me to a great extent if I have.

 

As long as the 2.8L block you have is '85 or later, the main journals will be the same as the 3.1L, which then is a drop in.

I did this with the Franken60, also bored .030" over, creating a 3.2L.

Yes, 3.1 pistons also need to be used.

 

the block I will use is out of an 85 s10 blazer so shoudl be good to go, and i think I found a crank on here im gonna buy. Just need to find some 3.1 pistons and such now. Im hoping to get 200 hp/200 tq oyut of this if possible