I have a 70 K5 with SM456 & NP205. I am pullin out that combo (and its for sale with everything including a new clutch with 8 miles) and have a 88 K5 donor truck. I want to put in the TBI motor and 700r4 w/ NP208. I need feedback on how to set up the fuel system. Some one already put in a large(er?) aftermarket tank in the truck but I will need a return fuel line and fuel pump for the TBI out of the 88 K5. Some one said use the tank out of the 88 or the other suggestion was use and external in line fuel pump and just add a return line. Whats easier? The tank on the 88 exits out the other side then ours. Suggestions?