69CulassConvertible

Hello and thanks for taking time to read this. I have a 1969 Cutlass with a tired 350 in it, and came across a 455 and 400THM to swap in place of the 350(s). The 455 came out of 1973 Delta 98 ( yes smog heads ). I intend to use Hedman headers, have read the threads pertaining to the swap, motor mounts etc. One question I have is the fuel supply, I will be using the 1973 Quadrajet 4 barrel, is there a difference in 2 line vs. 3 line ( fuel pump )from 1969 350 to 1973 455? Also, supply line size? This car isn't going to be built up for the track, just a sunshine ( convertible ) driver..with spirit. Thanks for any replies, and any other tips from those of you have experience with this swap would be much appreciated!

MDchanic

1. There should be no fuel line problems - just use the fuel pump from your 350.

2. The fuel lines in your car should be fine for what you're doing (and with that engine, you won't get any better performance by draining the tank anyway).

3. It is always better to start a new thread when you have a new question, rather than hijacking someone else's.

Welcome to ClassicOlds.

- Eric

joe_padavano

Done. To the OP: welcome. The third fuel line is the fuel return used on cars subject to high underhood temps to circulate part of the hot fuel back to the tank to cool off. Your car will be fine without it.

69CulassConvertible

Thanks guys, I appreciate any constructive comments.