I just spent the past 3 weeks working on my first samurai. http://www.zukiworld.com/forum/build-diaries-how-to-diy/saving-an-87-samurai-from-the-wrecker-budget-daily-driver-plus-trails-build/15/

Today I took her to work and along with the smell of bad jetting (too lean I think), the truck is slowing down traffic. She pulls strong off the line but stops making power around 50mph. I am running 4.91 gears and 31" allterrains. It has a Tri Y header and new full exhaust. The PO replaced the stock airfilter with one of those cone type filters.
5th gear is only available down hill.

read the last part of your thread

sounds rich, but even when tuned 1.3 is anemic

the axle gears help, but lower t case gears affect 2hi in samurai and you will benefit (you will do this even if you swap to 1.6; eventually)
play with this to see where you want/need to be:
http://www.lepayne.com/gears.html

But 1.6 FI is the answer to your question anyways. ..

Im thinking lean from the way it smells, but Ill check the plugs tonight. I havent found a guide for tuning the stock carb yet, any idea where I should be looking?
The idle is screaming fast, that could be another contributing factor.
The 4.91 gears are Tcase gears, Lowrange claims 18% reduction of high gear.

Check out the '88 Samurai Factory service manual at Ack's FAQ (see link in signature, below).

do a search for fsm.

I downloaded a FSM from suzukiinfo, awesome manual, I forgot how bad Haynes manuals are.
I am heavily leaning towards a 1.6L upgrade. How can I be sure Im getting a good engine before I go through the effort of putting it in?

buy it from a running donor or respected board member/vendor

try aftermarket4x4.com; tell him I sent you; he is a friend...

Thats a hard choice,I see Rocky Road sells a rebuild kit for around $250!!

Thats a hard choice,I see Rocky Road sells a rebuild kit for around $250!!

The cost of the rebuild kit is one thing to take into consideration, but don't forget the bill at the machine shop.  Don't know what is available around you, but you're looking at a couple hundred $$ for bore/hone, and the costs go up from there depending on what is needed (things like valve job, head machining, block decking, crankshaft grinding, etc.)

My vote would be to do the 1.6L swap.  The 8 valve is a super easy swap and there's no substitute for those extra few cc's. 

I bought an 8V from Sean at aftermarket 4x4, I am in the process of replacing the seals, belts and water pump. I am hoping to have it in and running this weekend.
Any one know where to get an FSM by tommorow so I can get the timing right, since I screwed up and lost track of it? Suzukiinfo doesnt have one listed for the 1.6L 8V.
If this is easy i am very glad I didnt choose hard.

I have a Vitara FSM here:

http://www.rhinoman.org/manuals/vitara/SE416_FSM.pdf

its pretty much all the same as the Track/Kick.

thanks for the FSM link!