I sold a customer a 3.9 out of a 90 RRC with V belts. He is trying to install it in a 95 Disco with serp belts. I told him he would need to use his old front cover and a spacer. He was cool with that. I had that backwards, you have to use a spacer to put a serp belt engine in a v-belt truck. When he tried to put the front cover on the crank is 1-2 inches short and doesn't have a key way. Is there a work around for this? Is he (and by extension me) just screwed?