having trouble installing my msd dis in my engine . it is a Merlin2 block and has been used before this is a new rebuild with a new msd dis kinda looks like the od of the shaft is to big to seat in the block . has anyone ran across this problem and is there a trick to getting this thing in also it is not the oil pump shaft holding me up any help would be apprec. thank you

I just put one in yesterday. It was snug to get in mine also, but I did get it in. I pulled it back out and you could see scratches in the area of the o-ring grooves. I polished it up and got it to go in though still snug. Once it was in it spun fine in the block.