87 gm 2.8 v6 motor swap out with 93 gm 3.4 v6?

Answer 1

Regarding rear-drive usage, yes. Front-drive is way more complicated.

Engines from front wheel drive cars do not swap to rear-drive vehicles, they are different, obviously.

The only real differences between a 2.8 and a 3.4 are internal.

The 2.8 was given a longer stroke to make the 3.1, and the 3.1 was then given a wider bore to create the 3.4. The only real differences are piston-related. There were other minor changes over the years, of course, but the engines are generally a relatively easy swap from one to another since most engine peripherals swap right over. One exception is that the water pump from serpentine belt applications turns the opposite way from V-belt applications, so you have to use the setup that native to the donor engine or swap the water pump.

Here's an excellent site for answers to questions regarding 60 degree Chevy V-6's and specifically S-10 series trucks. However, there's a lot of universal technical info on the engines and tips from experienced modders about potential swapping problems/solutions, including items specifically regarding 2.8 to 3.4 swaps.

http://forums.s-series.org