This is a past Thread with primergray with good info on dualcase setups.
We have many 91 P/Us with IFS using our dual case crawlers. Either V6 or 4 cylinder (and even V8 swaps), it is not a problem.
In my opinion, choosing a dual case setup will yield the best results out of any single modification. You will retain your stock high range gearing (city/highway), and will gain a 2WD low range, and a 4WD double low range ratios respectively. You will also gain 5 forward gear ratios and 1 reverse gear ratio, making your truck a 12 speed :talking: .
If you have a 4cyl engine (21-spline/or a Turbo (23-spline)), then you only need one adapter, the MC07. But if you have a V6(23-spline), then you will need two seperate adapters and will have to do-away with your factory chain drive (
http://www.marlincrawler.com/java/gearvschain.html) and replace it with a stronger gear drive transfercase using the second adapter.
In General, there are two different methods of aquiring a dualcase from us. (
http://www.marlincrawler.com/dual_mc07.html) One, and the most economical, is the Kit, and the other is the Unit. The Kt includes the basic and nesscarry parts to assymble the Unit, while the Unit is, ofcourse, the completed Unit. The Unit is a direct bolt on, right out of the box. While the Kit requires you to locate and aquire a 'donor' t/case that you will dissasymble, clean, inspect, and then use the parts provided in the Kit to assymble the completed Unit.
In the clause of a V6, If you choose the unit, you will still have to aquire a complete and good-working t/case to use as the primary t/case (replacing the stock chain-drive t/case). And if you choose the kit, you will not only need the afomentioned t/case to replace your chain drive t/case, but will also need a 'donor' t/case to dissasymble and use along with the kit to build a Unit.
Now this V6 will require both t/cases (Crawl Box (the Unit) and the main T/case) to be 23-spline (well, if you want to get technical, only the front Crawl Box is actually required). These 23-spline inputs were only found out of 2-years, 1986-1987 in any 4WD 5-spd Turbo Toyota P/U. These are getting harder and harder to find laying around in recking yards :ugh:, but don't worry, we sell 23-spline inputs for only $165 a piece. We Garrentee our price even to dealer-matched discounts, that we offer the lowest price due to our huge inventory (
http://www.marlincrawler.com/axleupgrade.html#turbo).
Regards,
BigMike
