I stuffed a 675 in the old Draggin' Wagon. Check oil pan front bolts - If 1/2" hex head, replace with socket head bolts so you can get the pan off if necessary. The gap between front of oil pan and cross member ain't enough to get socket in to bolts. The channel shaped steel that is bolted between the rear spring hangers of front springs will have to be shimmed down about 1" so it doesn't hit the pan. The left hand starter will be a SOB to change due to steering column so don't put an old worn out starter on it. I changed to a pull clutch which required a bunch of fabricating which I have tried successfully to forget.
Now, the water pump ------------ from my experience ----------------- well, really, I said the hell with chasing water pumps since my 673 pump was not shaped correctly, threw the fan in the trash (I didn't want to listen to it anyway) and put cooling fans in front of radiator (and junked the shutters). I'm sure there were other things that I'll remember soon as I submit this but that is enough to start with.
Plumbing up turbo was fun - I like to cut and weld stuff. Lucked into a rubber angle adaptor from God knows what to hook on to air inlet in fire wall. Also for the outlet side of turbo, I found a 90 degree adapter off IH school bus that looks like it belongs on this mess. My original turbo was passing a little oil and replaced with updated rebuilt unit. That really improved boost psi especially after replacing all manifold gaskets it blew out.
Seems like I had trouble with throttle linkage length but forget what. Probably just little cutting and welding cured it - I kinda like to do that anyway.
Enough for now - just one more thing - it made that 18,500 pound hunk of junk FLY!!!!!!!!!