1957 Volvo TP21 "Sugga"

Recently purchased a 1957 Volvo TP21 and am working on importing it into the States. 

For those who don't know, "In 1953 Volvo introduced a successor to the TPV for the armed forces, the four-wheel drive Raptgb 915 (military name), TP21/P2104 (Volvo military designation), P2104 (Volvo civilian designation). It was powered by the well proven 90 hp (67 kW), 3.67 litre inline 6 mated to a Volvo E9 gearbox." Only 720 were ever made. 

These things are absolutely fantastic (not to mention rare) but the era in which they were built leaves a few things to be desired.

The way I see it, there are a few different ways I could go. There's the full resto-mod route - a la http://gregsrestorations.com/volvo_sugga_resto_mod.html - but I want to be mindful of not completely destroying the soul of the thing and my tastes are pretty minimalistic anyway. Plus, I do not want to be doing anything that requires a full-blown chassis replacement or having to enlarge the engine compartment or anything like that. Personally, I like the look of this one - https://www.flickr.com/photos/28370466@N05/35508902633/in/photostream/

So, here's what I'm thinking:

• Repaint, easy enough
• Power steering, maybe
• Disc brakes, definitely
• Some sound deadening, new interior, that kind of stuff

The issue really boils down to what to do with the engine. I would ideally prefer to avoid doing anything that requires a new chassis, or that would mess with this thing's offroad capabilities. But, I think the non-synchronized gearbox will probably have to go. And the engine seems underpowered, given I believe the same engine was used in WWII era tanks from what I've heard. Maybe, then, there's something 1980s era that would be suitable? Part of me hates to get rid of the stock engine since it's so rare but getting that top speed over 50mph would be nice, in addition to all the other changes. I don't need many creature comforts, but I don't want to feel like I'm driving a tractor either. Then again, some friends have suggested just going electric but that makes me even more uncomfortable, haha. 

Thoughts? Would love to get a variety of opinions!

Late model Volvo inline 6 cylinder adapted to the original drive train. The one from a 960, normally aspirated. Probably lots of room for it.

First of all congrats on getting your hands on a Suggan! One of these is in the dream garage for sure, however the one in my head is rougher and a dedicated weirdo 4x4 Offroader... whether such an example even exists is questionable.

Mine would be with a diesel maybe? I'd love to put a big diesel Volvo motor out of some construction equipment or big rig in it for the giggles; difficulty be damned.

As an owner of a 65 IH Scout 80: whats wrong with a tractor motor?! The tractor thing is kinda fun in an off-roader if that's your goal, no need to destroy your truck trying to prove anything on the trails. It's like free hard-mode, without really risking killing yourself.

I'll be watching this one for sure!