The air leak in my 4.1 was traced down to a hairline crack in the butterfly valve pivot rod, so all I need is a new throttle body. Should I risk it with a junkyard kit, drop the $300 on a reman, or is there another option that won't require significant levels of hackery? Can I put a 4.5 TB on it? Does anybody sell bored TB sets?

Short-term is to keep the 4.1 running as cheaply as possible without losing functionality, long-term is to swap in a 4.9 longblock with a 4.5 TBI intake.

Thanks

Gosh, I've never heard of that. Someone must have really cranked down the mounting bolts.

Just get one from a junkyard.

Junk yard. If you are really mechanically inclined, get a throttle body from a 1981 368 cu.in. engine (8-6-4) Larger throttle butterflys bigger bore. Requires swapping over your 2 injectors and your TPS. All the fuel lines and vacuum hoses reconnect. Use a thick base plate gasket to allow the larger throttle blades to clear the holes in your intake manifold. Bump the timing to 12 degrees. Makes a huge difference in off the line throttle response, doesn't affect mileage if you keep your foot out of it! Did this years ago on my 84 Eldo 4100. Would actually chirp the front tires leaving a light!

carnut--

Did yours work OK? The car idled/ran fine? Would a throttle body from a 1980 Cadillac work too (6.0L TBI)?

I dont think so, different idle air configuration. When I first did it, I left the injectors from the 368 installed. The car started but ran so rich the converter got red hot!!. So swapped over the 4100's injectors. drove it approx 1 year converted and it was excellent. All you really do is provide more air at a lesser throttle angle so throttle response is better. Wide open throttle is still controlled by the intake manifold as far as how much air gets into the engine. The ISC was the same as far as mounting and adjustment, the TPS must be swapped simply because the wiring plug connected vertically on the 4100 and horizontally on the 368. So the 368's TPS wouldn't clear the manifold enough to get plugged in. To make it completely functional I installed a cruise control servo that a bead chain attached to rather than the rod on my 84 Eldo. So, everything was returned to normal. My latest 84 Eldo will get this mod soon. Not many 81 368's showing up at the wreckers nowadays!