i just read a post about an 87 that someone said it has both mech. and elec. fuel pump is this true ? same for my 86 ? i swaped to a 350 with mech. pump and seems fine but will i have fuel supply problems ? i noticed a purple wire running down driver side to under back seat but didnt bother with it since i pulled ecm and only put fuses back to stuff i need.

 

If someone who owned the car before you complained of vapor lock and took it to a dealer, they would have fixed it by adding an in-tank pump. I believe in 1987 GM set the carbed cars up that way from the factory, but the '86 models only had the mechanical pump.

The vapor lock issue was supposedly more common with L69s than LG4s though... there's a good chance you only have a mechanical pump if your car was originally an LG4.

 

thanks nate. was only worried about sucking fuel through in tank pump. now i have to figure where the large guage purple wire goes