Topic: I'm swapping for a 4.0L TB. Do I still have to grind the intake inlet?

[Sine Deviance]

I know it needs to be done for the 62mm TB swap, but does it also need to be done for the stock 4.0L TB swap? Also, the stock 4.0L TB isn't bored straight out, it goes about halfway (to the butterfly) and then it slants inward all the way around, like a horn. Do I also need to grind this out to get the best performance?

Thanks!

[FourbangerYJ]

The stock intake opening is 58mm, so is the opening on the 4.0TB so you don't need to grind the intake.
Don't grind the opening on the TB. You will need a new butterfly if you open it up. That is the differance between the 4.0 and the 62mm. The 62mm has been bored with a new butterfly.

[Sine Deviance]

Ahh sweet, that means I don't need a dremel tool right now! Awesome!

Thanks.

[Bounty Hunter]

You can remove the taper beneath the throttle plate without needing a new throttle plate.  You would want to be very careful, remove too much material and you will have a high-idle problem you can't fix without replacing the throttle body.

Let me know when you're ready to step up to the 62mm TB, I have 5 on hand now.

[jfrabat]

I have the 62mm TB, but have yet to grind the intake; so you can have the 62mm TB without the grinding, but you will not be taking full advantage of the 62mm body...

[Sine Deviance]

You can remove the taper beneath the throttle plate without needing a new throttle plate.  You would want to be very careful, remove too much material and you will have a high-idle problem you can't fix without replacing the throttle body.

Yeah, that taper is what I was talking about :)

Let me know when you're ready to step up to the 62mm TB, I have 5 on hand now.

I will. It's gonna be a little while for two reasons. 1. I'm not yet confident in my ability to grind out the intake inlet. 2. I'm pretty happy with the 4.0L TB right now. The next stage for me is Mustang injectors (she's running a bit lean now) and a 1" TB spacer (I want to make this myself, my first real fab project. I'll go ahead and bore it 63mm for the future.) Then, the e-fan with an alternator to push it. Once I get those things done and I'm about to start on the exhaust I'll probably go ahead and move up to the 62mm TB.