driveshaft help needed

[underground racing]

Recommend place to buy(more to east better, shipping to europe u know). Looked from net mancini, strange, mark w, dennys... I Think I go 1350 joints, but mild DOM steel??? Crome moly(worth the xtra investment)?? And Slip yoke for 727 is clear, but pinion yoke 10 or 30 splines??? Orginal 489 case(3,23) from B-body. And conversion yoke(from strange I found that) 1350 to 1330(=7290?) to fit my 8 3/4, they offer two sizes 1,125" and 1,0625", which one is correct. I Don´t have a race car(12-13s). A-body+RB.
Have someone changed extension housing bushing(slip yoke) from the behind(without removing extension housing). Cause Mopar perf has made that little bit harder=that opening to remove the snapring is nolonger under tailhousing, its moved to side! Brilliant idea!
Maybe I cut a hole to my floor, to get access??