I know Muncies and Tremecs are good, but they are expensive.
The last swap meet I went to I saw Muncie 4-speeds starting in the $750 to $1000 range. Tremecs are usually more.
The only transmissions you can buy that will handle any abuse at the power levels you're talking about which won't cost at least as much as the Muncie would be something like the SM420 and SM465, which are also made by Muncie.
If you are committed to running a car-type performance manual transmission you'll have to spend some coin to get a stout one.
If you want an overdrive you'll spend even more. If I wanted an overdrive manual transmission I'd look hard at the Tremec 5- and 6-speed options. I'd expect to spend $2500+ for a new one.
I have a DNE 4+3 which is a Super T-10 with an automatic overdrive. Its a stout transmission that can take some abuse, but it highlights the downside of having an add-on overdrive over having an overdrive gear in your transmission.
If I were replacing it with another manual it would definitely be something like the Tremec. I think more likely though I'm going to trade the car for one with an automatic.
