Which is the best turbo? GM4 or GM8

[Blackie94TD]

I have a recently overhauled chev 6.5TD with new IP and turbo. I noticed yesterday the turbo that was installed was a GM4 BW. I have been researching and found there were others out there available such as the GM8. What are the benefits of the GM8 over the GM4? I am making other upgrades to fuel and cooling system. I already have made induction and exhaust improvements with the Banks Stinger System including boost and pyro guages. FSD Sync Kit is next(posting DTC 35 and 36) and the lift pump has just been replaced with a OEM pump. Does anyone know anything about these turbos?


Blackie94TD
1994 Chevy long bed ext cab 2500, 6.5 TD, 5 spd manual trans(SL with OD), 411 gears, 270K completely rebuilt at 250K, new IP, turbo, injectors and gp's,
Banks Stinger System exhaust, induction and guages(TB and Pyro)

[Husker 6.5]

The GM4 was used until I believe late 96. The main difference is that the 8 has a redesigned impeller/housing geometry that brings it up on boost a little sooner than the 4 (but no higher boost psi). The other two models are for the H1/van (top mount) and for pre-'94 non-computer engines.

Husker 6.5:)

[Blackie94TD]

Thanks for the information. You answered my question.

[Husker 6.5]

Thanks for the information. You answered my question.

No problem. That's what the forum is for, sharing information and experiences.:)