hey guys i bought a set of gt 40 heads and im going to most likely run an explorer intake mani thats gasket matched to the heads.. so my question will this be a good set up for my car and can i run a aftermarkey tb like a 75 or 80mm on the explorer mani?
I would run the explorer 65mm TB. I have that on my 302 and it is more then adequate (sic?) to feed my engine. You will need to swap throttle arms but that is it. I also machined out my EGR spacer to 65mm to take advantage of the TB. Unless you have a serious engine you will not need anymore then a 65. With stock GT40's you will not get to the point where the TB is the limiting factor.
There are 3 ways do do the throttle body linkage, so I will give you all of them.
The Explorer TB could have been real simple if I had a gas welding torch or taken the TB to a welding shop. Just grind the mushroomed part of the TB shafts so that you can pry the linkage arms off. Then swap the stock arm onto the Explorer TB and braze it onto the shaft. It Takes about 3 minutes or less worth of work with the torch, so it shouldn't cost much. Just be sure to protect the TB return spring from heat so that it keeps its spring tension.
I didn't have access to a welder, so I fabb'ed a plate in my shop. I took about 1.5 hours to do it, it was a measure, cut, and fit type of operation.
This is what I did:
Make a drawing of the position of the old throttle body linkage arm and its angular position relative to the centerline of the throttle body. Remove the ball stud off the explorer TB to make way for the adapter plate. Drill and tap a 10-32 hole in the linkage parallel to the TB shaft. Make an angle bracket out of 1" angle iron 3/8", drill a 3/16” hole in the center of each one of the legs. Then bolt it on where the hole was drilled & tapped. Then make a circular adapter plate out of 1/4" thick aluminum to bolt the two linkage arms together. Then bolt the aluminum plate to the existing linkage, and the angle bracket. Next mount the arm with the ball stud off the old throttle body on the adapter plate using the drawing to get the angle correct. You will need an aircraft type countersink for one of the bolts that secures the plate to the explorer linkage arm. It ends up being under the arm with the ball stud for the linkage. It works great and looks neat.