Hi guys. I am new here! My name is TJ and I have a passion for bowties.

I may not have a Chevelle, but I was led to this site for good BBC information/discussion. I currently have a 99 Z28 and a 90 RS Camaro, and the 90 RS is what is going to be going under the knife.

My question is complex.

I want to know why it is not possible to convert a Mark IV to a 1 piece rear main seal.

My goal is simple.

I want to run a Gen V/VI oil pan with crank sensor timing cover so I can run a BBC off the LS1 PCM, using coil packs and an injector fed manifold.

A Gen V/VI block works fine, but since the Gen IV is a 2 piece RMS, you cannot run the timing cover/oil pan combo needed to do this.

I have scowered the net for a few months now trying to figure out what I could do to run this off a Mark IV and all answers just point to no, but I don't have any conclusive evidence on WHY it cannot be done. I only find threads about Ford guys doing it.

Until my 99 is paid off, I can't buy the block and the two timing covers and two oil pans to see exactly what is so different.. but maybe if it's just the front of the pan that's different, maybe frankensteining the back half of an older pan to the front of a new pan..

I kinda figure I am screwed, but tossing ideas back and forth never hurts.

why not just get a gen vi block from a junkyard??

The shape of the rear flange where the seals fit is entirely different, though you can go the other way around: two piece seal onto a one piece block using a special adapter. Also, the balancing is different: the two piece seal had additional weight on the crank flange, the round crank flange of the one piece required a different balance flywheel.

As mentioned, use a Gen V or VI block.

John

I just went through this. Wanted gen 6 timing cover and crank sensor on my two piece 540 which I just built on a brand new bow tie block. Solution is to swap the nose of a two piece pan with the nose off a one piece pan. gaskets need to be modified also, need the nose piece of a gen 6. There is no way to convert a two piece block to a one piece.

We finished welding the pan recently, it needs baffles installed won't happen instantly but eventually I can get pictures up somewhere.