I ask this only because I don't have a Tracker to look at right now ( ), but is the front clip removable, or is it welded on?

what do you mean by front clip body or chassis what year

That's a yes and no question,
you can remove the fenders and
the top peice where the hood latch
bolts to (core support) and of coarse
the grill and radiator, but the under
pinnings are welded to the body, like
the inner fender, the headlight mount
points, and there seems to me there was
somthing down by the bumper, but I can't
remember exactly right now.  Ohh ya, the
part that the middle support for the grill
bolts to.

That's about it, you can remove teh engine
thru this spot if need be, is that what you
were thinking, or you have a bigger engine
you want to stick in there

Wild

That's a yes and no question,
you can remove the fenders and
the top peice where the hood latch
bolts to (core support) and of coarse
the grill and radiator, but the under
pinnings are welded to the body, like
the inner fender, the headlight mount
points, and there seems to me there was
somthing down by the bumper, but I can't
remember exactly right now.  Ohh ya, the
part that the middle support for the grill
bolts to.

That's about it, you can remove teh engine
thru this spot if need be, is that what you
were thinking, or you have a bigger engine
you want to stick in there

Wild

I think hes doing a SBF

stu

Stu and Wild hit it on the head. I'm thinking about a 5.0 Ford if I can't find anything else in the 4cyl vein (the uncle that's selling me the landcruiser axles also mentioned having a running Datsun pickup engine with 67k on it... he swears by that engine, but I don't know how they reliable they are, or how much they'd like forced induction), so more room would be needed.