Much to my shock and dismay the TR heads don’t actually fit on the 400 block. The bore spacing of the 2 engines is 94mm, just like the 308. I was just ASSUMING that just like the 308 where QV (4 valve) heads will basically drop right on to a 2v block, the TR heads would drop onto the 400 block but that was not to be. The bolt pattern doesn’t match nor do the alignment pins, coolant holes, oil feeds and of course the 400 has a timing chain where the TR heads are designed for a timing belt (I knew about and was mentally prepared for this problem).

This is where a wise man would admit this project was a bad and poorly thought out idea….so I’ll continue by cutting open the stud holes to gain access, then weld them solid and re-machine them in the correct locations for the TR heads. It’s not so bad, 10 are in useable locations so I only need to move 18.