Get it! They are fast, fun to drive and dependable. The only bad thing is that the timing belts are a PITA to do.
On a MkI (1985-1989 first gen, aka AW11) they're not bad at all. MkII (second gen, 1991-1995, aka SW20 [Turbo] and SW21 [NA]) are tougher to do a timing belt on but still not impossible if you have a little time and can think creatively.
...it's an 85, 5 speed...Apparently it needs a fuel pump. ...What the chances that motor could be swapped into a 4x4?
'85 is the best year IMO. I like the look of the black bumpers and rub strips better than the color matched stuff that later years have. It also gets the auto climate control and front and rear sway bars. Make sure it's the fuel pump and not the circuit opening relay that is causing problems; people love to point at the fuel pump any time they see a lack of fuel, but it's not that simple, and dropping the tank is no fun.
4AGEs are great sports car engines, but I would not want one in a 4x4. They are rather weedy down low and need to be revved to make decent forward progress.
BigMike, your car looks beautiful, and it you did a hell of a job on that engine build (nice job combining the SC with the NA intake manifold!), but I have to correct several things you said here. I don't claim to be a wizard, but I do own an '85 myself, making around 170 horsepower without a supercharger, and I spend a good portion of my day selling MR2 parts to people all around the US and the rest of the world. Let's just say I'm fairly familiar with them.
The good thing about this swap is that the AE86 Toyota Corolla GT-S uses the same engine as the MR2, and as we all know it uses a W50/52 2WD transmission which uses the same exact bolt patter as the Hilux G52/54 and W56 (and even the Tacoma W59).
So bolting a Marlin Crawler Dual Ultimate behind a 4A engine is all bolt-on 
.
Negative on that. The A-series engine never got a W-series box mated to it. They were all T50s, which are pretty fragile at high power levels and nothing like a W or G series, and never used in any 4WD aplication that I'm aware of. There are custom bellhousings available out of NZ that will mate an A-series to a W5x, but they're obviously not factory Toyota parts.
Find out if it is a GT-S "Unlimited" version. If so then it will have sway bars front and rear, which is the only MK1 MR2 with this feature.
Geetawhowhatnow? Never heard of such a thing. Japan had a few goofy short run special edition versions (G-Limited, Black Limited, etc), but the US never got anything like that. All '85 and all supercharged MkIs have a rear sway bar.
The downside to the early 85-86 models are that they have the weakest MR2 transaxle ever used (the C50) and they have the smallest brakes ever used (1" smaller rotors than 87-89 version). Even worse, the smaller rotors ride on smaller spindles with smaller wheel bearings. Of course if you are looking for lots of power, you would immediately upgrade to the E-series supercharger transaxle (E56) (JDM versions come stock LSD-equipped) or use a 6-speed variant (C160) from Japan/Europe. These use larger and heavier axles with larger spindles and wheel bearings in the rear.
C50s are not fantastic, but will hold up with proper maintenance. My C50 still works pretty well and it's never been apart. The most common issue is fifth gear pop-out, which can be addressed. '85-'86 brakes are small, but adequate for a street car that isn't frequently pushed hard. However, your comment about smaller spindles and bearings is just plain incorrect - someone must have slipped you some bum information. All MkIs use the exact same hubs and wheel bearings. C160s use the same axles as the C50, but you're correct that E-series trannies do use heavier axles. The hubs and bearings remain the same as all other MkIs though.
