5.3 to SM465 fitment issues

[Trashy]

I'll start off with my truck details, 68' C-10 long bed, was a 250/SM465, factory perches and bell cross member.
So I slung a 03' Gen3 between the rails this afternoon and my driver side cylinder head is up against the throttle linkage on the firewall and I still have roughly 3 inches to go for the block and bell to mate together. I thought I'd seen this work out in a couple other threads but maybe I misread. Anyway the only solution I've come up with at this point is to move the transmission forward. I haven't had any luck with searching, especially with photobucket killing lots of good build threads. What other options do I have?