1G Alternator belt sizes for different pulley setups

This is just a general post including some of the Gates belt part numbers for a few different pulley setups that I've had. I haven't seen a post like this so hopefully this helps some people out in the future. I have personally ran all of these listed and have verified they have worked fine.

Gates Micro V belt site for part numbers and sizes:

Gates Micro V 4 rib site

These are all for at least the MCR "Saturn" style in the factory location and factory tensioner arm + Morrison Fab Saturn alt adapter. It might also work for the GM Saturn alternators but I don't know for sure if they use the same diameter pulleys. There is likely some variance between setup due to possible differences in clearances when clearancing the block, oil pump housing and the alternator housing itself.

I also don't know if these work on a 2g since I don't have one to test with nor the knowledge if they really are the same, so use your own discretion.

Pulley setups:
1:
Stock crank pulley
Evo spec underdrive water pump pulley
Kiggly Under Drive Pulley
Gates Part #: k040399

2:
Stock crank Pulley
Evo spec underdrive water pump
MCR Stock Alternator Pulley
Gates part #: k040390 (fairly tight, Can try: k040395, might be too big)

3:
Fluidampr Crank Pulley
Evo Spec underdrive water pump pulley
MCR Stock alternator pulley:
Gates Part #: k040395

 

[TheBrownMike]

4:
Stock crank pulley
Stock water pump pulley
MCR standard (2.5") alternator pulley
GATES Part# K040388

This landed mine about 3/4 toward the front of adjustment bolt with MCR Eclipse 1-wire alternator and Morrison Fab adapter. A 385 or 384 belt may work as well, but have not checked.

 

[peon_slayer]

4:
Stock crank pulley
Stock water pump pulley
MCR stock alternator pulley
GATES Part# K040388

This landed mine about 3/4 toward the front of adjustment bolt with MCR Eclipse 1-wire alternator and Morrison Fab adapter. A 385 or 384 belt may work as well, but have not checked.

When you say stock alternator pulley from MCR was yours a 2 in or 2 and 1/2 in pulley because I had to call and ask which they were putting on mine.

 

[TheBrownMike]

When you say stock alternator pulley from MCR was yours a 2 in or 2 and 1/2 in pulley because I had to call and ask which they were putting on mine.

2.5" OD, I'll update my post as well for clarity. I said "stock" as I didnt request a specific one and assumed it was standard.

 

[peon_slayer]

2.5" OD, I'll update my post as well for clarity. I said "stock" as I didnt request a specific one and assumed it was standard.

Thanks I tried the K040388 and it was in fact the correct belt, I also am not using the factory tensioner but more of a turn buckle style one and it worked great. Thanks for suggestion!