360/5.9 Performance Mods Basics: What opens them up?
#23
If your water pump is original, might just as well change that too, as it has to come off anyway.
Something else to consider is: If you haven't fixed the plenum yet, there is a fair bit of overlap on the intake, and timing set... it would save you some cash to have both done at the same time.
Or, you can save yourself several hundred dollars in labor, and do the job yourself over the course of a weekend.
#27
Throttle body spacers
throttle body spacers on efi will not work like it does carbs at that point its more useful as a paperweight a old school hotrodder told me 3 key tips cold air in and hot air out so the colder air u can get into the system headers down to 2 to 1 exhaust nd get the exhaust out wit less bends ie straight out the back bumper get a good highflow cat nd freeflow muffler u will see gains nd dont mess with ur computer get better injectors bosch 4 hole are pretty good nd u can run 87 and be fine dont need to go all out nd retune ur truck
#28
throttle body spacers on efi will not work like it does carbs at that point its more useful as a paperweight a old school hotrodder told me 3 key tips cold air in and hot air out so the colder air u can get into the system headers down to 2 to 1 exhaust nd get the exhaust out wit less bends ie straight out the back bumper get a good highflow cat nd freeflow muffler u will see gains nd dont mess with ur computer get better injectors bosch 4 hole are pretty good nd u can run 87 and be fine dont need to go all out nd retune ur truck