I installed a 454 in my 1986 C20 and also installed a TBI from a 91 suburban along with dual GM in-tank full pumps from a 1990 C30 It turned out Awesome !! It's not as hard as you think but if you have any questions get ahold of Affordable fuel injection Their the best when it comes to GM injection. You can get any Info/ parts/wiring harness/ custom ECM chips... you name it (ask for Mark)
I was so happy with the way my 86 turned out that I ordered a TBI kit from them and installed it on my 51 and im even more pleased with it... the wiring turned out nice and it Fired right up on the first crank
I think TBI is the only way to go thumbs_up
Good luck and post some pictures of the install
Todd

Some people are like Slinkies, Their not really good for nothing... But they still bring a smile to your face when you push them down the stairs.

1951 3100 350 TBI Gallery Toddzilla... "$old"