Gearboxes and making them fit different engines

Almost anything can be done given the time and money to do it.
If it hasn't been done before there's probably a good reason for it though saying that there's very little that hasn't been done before.
I have a type 9 mounted to a 1275 A series, 50's technology mated to 80's technology from two very different cars and companies yet they fit with only one custom part (bell housing) and a few parts bin components.
Spigot bearings and bushes can usually be made and clutches are quite often just a hybrid to get the input shaft spline mated with a matching pressure plate.
It gets expensive having to buy parts that either don't fit or you find you only need part of a kit.
I think you'd need to post specifics of make model etc to get any real answer, but by far the most expensive and difficult part is the bell housing.

Excellent stuff, thanks!
The pics help enormously!!
Putting my thicky head on, lets say you have a gearbox, fly wheel, clutch etc from one model. Is it feasable to get that flywheel to fit the donor engine end? Ive seen flywheels redrilled and, i assume, the semantics of doing it would be similar to redrilling car wheels? In theory IF the whole transmission side is taken lock stock and barrell to the donor engine, would it be then a case of fabricating a bellhousing to brring the two together and ensure there is somewhere for the starter ( I assume it would be from the engine the box came from) to be bolted to? If we look at the bellhousing as, basically, something that brings engine and box together then acts like a giant dust cover, would that way of thinking take you any further forwards?

Cheers fella, all info greatly appreciated!

Anything will fit to anything. The challange is to do it for as little cost as possible whilst arriving at a solution which is durable and of the correct specification for the planned use.

I think the only way to help in this case is to know exactaly what you can get for free, what you've already got and what you're trying to do. If you can answer those questions and maybe chuck in a couple of pics then you're onto the home straight.

The next thing to do, assuming all goes well with above, is to get the engine out on the bench and line it up with the gearbox and see how well it fits. I've done a lot of this recently and is by far the best way to do it. It busts a lot of bullsh1p. At the pub people will tell you all kinds of things about what will bolt to what. Until you try it for yourself there aren't many other ways of finding out the truth.

Examples. 2.3 long-throw crankshaft mounted in a 2.0 block. The online consensus was that the webbs would hit inside of the gearbox. Truth is they clear by miles. Worst thing is that the webbs hit the bottom of the pistons and the con-rods hit the bottoms of they cylinders. You have to grind a bit off the end webb as well as it catches.




Online rumour: Inlet manifold from an 80s Saab has to be swapped if upgrading to the 2000s cylinder head. Truth is, the old manifold bolts to the new cylinder head almost perfectly. I'll use a 2mm aluminum plate cut with a dremmel to cover up the small injector port holes on the side of the cylinder head.




So it pays to suck it and see. Try and bolt the two bits together and see where the gaps are.

All the engines I've ever seen work on the same principle of using the flywheel to drive a clutch which is connected to a splined shaft comming out of the gearbox.