1968 bug that needs a 5 speed.

[Bruce2]

If you can't afford an IRS pan, you can't afford a 5 speed.

The 2 most common 5 speeds to use are the Berg 5 and the Porsche 901 5 speed. By the time you rebuild a Porsche trans ($$$$) and install it with all the extensive fabrication work, you will be into it for at least $2-3K.
The Berg 5 can be made with swing axle to bolt into your car, but the cost of the parts alone are near $2k, then you have to get it built. Any upgrades you need will easily push it well over $3k.