Hello, J body enthusiasts! I have been on a quest for a couple hours now, and answers seem to be almost nonexistent! I believe my thirst for this “forbidden” knowledge started with a Facebook post about a J2000, where I learned that some J body cars in the 80’s (and some other GM cars from the 70’s-80’s) got a strange engine option; Opel derived four cylinders. After I read that, I figured, hey, let’s figure out what bellhousing pattern these “family 1/family 2” engines have.

That’s almost as far as I got, because who knows! I have discovered that Opel and Isuzu designed the Chevette together, and that a T5 transmission from a Chevette bolts up to an Opel GT engine (foregoing the top two bolts on the engine), and the Chevette used an Isuzu engine- the G161z, available in all “t” body cars. The engine In an Opel GT being a 1.9 “cam in head” engine.

That’s it, that’s all I’ve gathered! I can’t find any more information on the subject. So I’ll bullet point some active questions below.

- Do the family1/2 engine from Opal use a common bellhousing pattern in all applications?
- Do those bellhousing patterns match the Opal “cam in head” engines?
- Does the bellhousing differ in from wheel drive vs rear wheel drive applications?
- Does the Isuzu engine from a Chevette share bellhousing patterns with other Isuzu engines?
And many other questions, I’ll take whatever answers I can get. What will these answers get us?

- if it is proven that many Opel or Isuzu share bellhousings, it can open up many swap options not just for J cars, but all cars!

That’s it! The only reason we need! That’s what I’m after, is good swap information. I’ve learned that Isuzu and Opel had some hot, hot engines in comparison to our mostly lackluster options here (2.2 ohv? Snore. Quad four? If you have a matching bellhousing!) However, with some good info on these bellhousing patterns, we can find out not only if we can swap a turbo engine (Opel, or Isuzu) into a J body, we can find out if we can swap them into anything! (Turbo Isuzu S10, anyone? Hell with a v6!).

If you’re really curious why I’m wondering about this, it’s not about J bodies (but it is- some J bodies had Opel Drivetrains), it’s about not being limited by American options. You know, the typical “I wanna swap my Fiero’s Iron Duke- do I go underpowered v6, big ‘ol v8, or what?” Situation.

So- anyone here a Guru with Isuzu bellhousing patterns, or Opel bellhousing patterns? Anyone able to take measurements and make a quick sketch? Let’s uncover the info we can’t find, to make a more fun world for tomorrow.

I've got nothing of value to add here but applaud you for doing something interesting.

I hope someone here can help!