I did not read the who post it was trollish...
You should use the correct heads.. 6.2 on a 6.2 and 6.5 on a 6.5. the difference in the turbo heads the the pre cups. on a non turbo engine they are a lot smaller and are made for low end and good MPG. The larger the cups the more power the engine can make but were not talking 1000 HP differnece. So just run what you have.
Don't wast your time with 6.5 lines,pumps,injectors. 100% wast of time. Run your 6.2 stuff and turn up the pump a little.
a 6.2 pump and injectors can be cranked to totally over fuel and melt down a turbo 6.5.
I just am finishing a conversion on my 1995 k3500. I installed a military DB2 pump, lines, and injectors (6.2 hummer)
If I hold the peddle down long enough the engine would be a flaming pile of slag. The 6.2 pump turned up has WAY WAY more fuel then the 6.5 turbo can ever need.