What needs to be done to the block to get it prepped and cleaned for the new head thats going on next week? Any special stuff that needs to be done? Also, whas the process for bottom tapping the holes for the studs (what siz tap/ where to get it?)?

 

the block really just needs to be checked to make sure its flat. if its not it needs to be decked

 

I mean just cleaning it and bottom tapping the bolt holes? its pretty good on straightness

 

Bjans is that 583 hp and 1156ft/lbs with the Dragon Fire pump? What hp rating are your injectors? Don't mean to high jack your thread, But just wondering.

 

Yes it is but on the dyno it hits a brick wall at max hp! I run out of air. It smokes like a freight train though. I'm in the process of doing the head work and twins and get the full potential out of the pump! Its awesome. My injectors are 150 horse

 

Good call on chase threading the holes. Head stud is 12mm but I don't remember the pitch. It is a common one
This is a very overlooked process until the popularity of studing. My father taught me to chase thread ANY hole in a casting (early 70's) to clean up the accumulated blow-by, rust, etc. Amazing how much comes out of the holes around a thermostat housing. More amazing how much comes out of the block at the head even on a N/A diesel. A lot of soot is forced into the holes.

Get a true bottoming tap. Run the tap down until you find the bottom of the hole. Mark the tap and do it again and again and again. You will usually find a hole that is tapped as deep as the rest. As long as the hole is deep enough, you can finish the threads. Auto tapping machines always tend to leave one hole a bit shallow. Doesn't get noticed with head bolts, but shows up when you go to studs. Studs should bottom on the casting, not the threads.

Blocks tend to run very true. Roll it over and check around the main bearings for cracks. Get a girdle.

 

M12x1.75mm. If you can't find a real bottom tap, you can always trim one and make that work. Just keep it cool, last thing you want is a broken tap in a hole.