And I finally decided on...

...the Alfa Romeo V6.

(The website name is a bit of a giveaway, I know.)

A number of things made me choose this engine; it is a lot more revvy than the v8s (and a number of the v6s); it produces the right amount of power (in 3.2 guise at least); it can be tuned and supercharged (being a v6 and hence rather shorter than a v8, there should be room to fit a centrifugal type supercharger); I can afford one. Plus, it's got that something about it...the sound, the looks...rather than stick a plastic engine cover over it like virtually every other manufacturer does, they've gone to the trouble of making the engine itself look attractive. I like that. And I can pretend I'm saving money on engine bling.

Here's what it sounds like:

Any questions? :-)

Of course, on the downside, there's the slight issue of there not being any RWD gearboxes which fit. Tuning is expensive (seems to be a common trait, that), and it looks likely that I'll have to use a 3.0, rather than a 3.2. So plan "a" of supercharging seems quite likely.

So as you can probably tell, I can't claim it was a purely rational decision, but then that's not the point is it!

Gearbox Grafting

When it comes to adapting a gearbox, there seem to be two main options that people have done. Option 1 is to follow in the footsteps of the one called Owelly, and make your own bellhousing to join your gearbox to the engine. Option 2 is to chop the bellhousing off of an alfa gearbox, and make up an adaptor plate to join it to the gearbox of your choice, as per Mr. John Mor. Option 3 is to do something new...

Personally I'm leaning towards the second option as it looks simpler, though it does mean trashing a geabox just for the bellhousing.

Gearbox Choice

Given that I will have to build an adaptor anyway, I'm less limited in my choice of 'box. The main thing will be something which is RWD, strong enough, and which has a removable bellhousing.

The standard sierra box (Ford Type 9) is out because it wont handle much above 190-200hp (so I'm informed). BMW boxes don't (generally) have removable bellhousings. There are a few toyotas which would fit, W58 and R154 boxes from the Supras (the R154 is known for being very strong, very large and heavy though). The Borg Warner T5 from the Sierra Cosworth fits the bill, as does the one from the Honda S2000. The Alfa 3.2 GTA cars have a 6 speed box which is a good match for the Honda, but the Honda doesn't have a removable bellhousing either.

Decisions, decisions...