I have a 88 s-15 Jimmy 2dr 4wd with a 2.8L. I want to put a bigger engine in it. What whould be the biggest size engine I could put in with out having to do alot of major replacing of parts . Any help or suggestions whould be very grateful.
<font face="Comic Sans MS">Without swapping transmission, buying an adapter for the t-case and other stuff, the biggest engine you could swap in is a 3.4L out of a RWD GM car. You'd need an electric fuel pump since it has no provisions for a mechanical pump. You could swap in the fuel injection from that GM donor car you get it from or you could put a carbuerator on it I believe. </font>
From what I hear a 4.3 TBI or Holley TBI on a ported 2.8 intake works great with the 3.4. Swapping the Camaro/Firebird FI system would be a pretty big job and you may have emissions problems with a carb.
The 3.4 is a bolt in, but there are some flywheel issues. The camaro/firebird flywheel will not work. The 3.4 is internally balanced, you would have to check if your flywheel would work.
Search back, this swap has been discussed here several times. You will find just about everything you need to know. Also http://s10-4x4.com has a discussion board for 3.4 swaps. The Isuzu board http://www.itog.com also has some good info.