Transmission Swap

I heard that the 88 fiero 5 speed transmission is able to handle horsepower better than the earlier ones. Is this true?

If so, is it possible to swap an 88 transmission into an 85 car without intense modifications?

"Handling horsepower" is a relative term. How much power? It's true, the Muncie 5-speed in the late '87/'88 is a bit better than the Isuzu that was in the earlier cars. It would take a helluva motor to over-power it, though. What is it you have in mind?
Swapping it in would require a variation in the shifter. I would check with Pontiac or someone with part numbers, and see if the cables are the same for the '88 as the earlier cars. I know the "hookups" for the cables are different.

I too wish to have a V-8 in my fiero, but from what I have heard the Isuzu's are apparently too weak for them. All I am looking for is a 300-350 horsepower range engine. I'm sick of my 4-banger :)

The Getrag/Muncie 5 speed was designed for 2.8@3.1 V6 engines as well as the high output Quad 4 (however, quad 4 getrags will not fit a V6 unless you change the bell housing) and do hold up better then the Isuzu used on ALL fiero 4 cyl models. I can't answer your question about the 88's but I do know this: There were 2 different getrag 5 speeds used in the Fiero, option codes MG2 and MG3. The MG2 was used in late 86 and 87-88 Fieros and had 3.61 gears. Unfortunatly, I have NO information on the MG3 except it is a muncie/getrag 5 speed, it was used in the Fiero, but wasn't used in 85 or early 86 models. Perhaps the MG3 is the "better '88" you've heard about, but I can't be certain. FYI, here's an awesome read about getrag 5 speeds and how to take one from another GM car and make it work in your Fiero: http://www.rodneydickman.com/GetragArticle.htm

Ok thanks.

Also, I was offered (yesterday) an 88 fiero. It does not have the engine in it, but it used to have a 4 cyl. Since its not a V-6 transmission is it still a Getrag?

No, only Isuzu transaxles were used in 4 cyl Fieros.

To find out for sure what transaxle a Fiero has, open the front hood and look on the Driver's side inner fender. You'll find a tag here with the vehicle's RPO's (regular production options)
The transaxle codes are:

MT2 - Isuzu 5 speed (all 4 cyl 85-88)
MG2 - Muncie\Getrag 5 speed (V6, late model 86, 87-88)
MG3 - Muncie\Getrag 5 speed (???late model 88 only???)
MM4 - 4 speed manual (no other info on this)
MM5 - 5 speed manual (no other info)
MY7 - Isuzu 4 speed manual (no other info)
MY8 - Muncie 4 speed, 3.32 gears (84 only)
M17 - Muncie 4 speed, 3.65 gears (all V6 85 and some 86)
M19 - Muncie 4 speed, 4.10 gears (84 only)
MD9 - Turbo Hydromatic 125c 3 speed automatic (???4 cyl??)
MV9 - Turbo Hydromatic 200c 3 speed automatic (???6 cyl??)
MX1 3 speed automatic (no other info on this code)

for the V6 Models, 85-early 86 used the Muncie 4 speed, late 86 to 88 used the Getrag 5 speed. ive heard the 4 speed is stronger and more quarter-mile friendly

and the automatic was the TH125c in all models i believe, my 86 GT has it