Thread: Series III downgrade to Series II

I've got a 3800 SC III out of a 2004 GP GTP. I'm going to stuff this thing into a 1988 Pontiac Fiero GT. I've decided that for my application, I'd like to downgrade to Series II setup.

I know I need things like the throttle body, ECU, PCM, wiring harness... what else do I need?

btw, I'm also refreshing the engine while it's on the engine stand. I'm doing some preventative maintenance. So, I'm replacing the water pump and pulleys and belts... etc. What else should I replace? I work at an auto parts store and I get about 30% off, so these parts are cheap.

Are the wiring harnesses different?

I guess I'll have to reprogram the ECU/PCM.

I've got a black box... I guess it's the BCM... do I need that?

Say, is the stock timing chain a roller type? Now would be a good time to replace it if need be.

I'm going with a manual... that's hard to program if I remember correctly. I'm also avoiding having to reprogram the ECU every time I change the hp a bit (avoiding limp mode). I also want to avoid the sensor pedal and throttle by wire setup. The Series II just seems like it would be much easier. Also, Fiero guys can bypass Passkey II, but the Series III VATS gives us problems.

I've got a black box... I guess it's the BCM... do I need that?

Say, is the stock timing chain a roller type? Now would be a good time to replace it if need be.

The oil pan leaks. Is this just the gasket or is there another seal there?

I'm guessing that the gasket is a better idea than the rtv since it's heat cycled so extremely.

Is this plastic damper known to fail? Here's a pic I found of one. Is it that thing that rubs against the chain?

It looks like a non-roller chain. Any complaints about that?

Who makes throttle body adapters for Series II throttle bodies to Series III superchargers?

Is there a specific Series II throttle body I want or are they all the same?

Rollmaster Roller Timing Sets: 3800 Performance

The only double roller I've found is $300 (above). That sounds ridiculous compared to the one in the link below (I know it's for the wrong engine). The single roller I saw was $150, which is more than I want to spend since I'm never going to see over 300hp.

CHEVY V6 HP True Roller Timing Chain 196 231 3.8L:eBay Motors (item 220418317645 end time Jun-18-09 20:08:13 PDT)

The 99-05 (non TBW) throttle bodies have the mass air flow sensor already in them, right?

Any other parts I should replace or upgrade? Oil pump pickup... supercharger rebuild... random bolt... certain gasket... starter... A/C compressor...

Nothing on the roller chain?

Are the Series II and Series III identical internally... talking about cam and head specs? I'm asking because that Series II ECU will be programmed for Series II specs. I'll get it tuned anyways, but I'm trying to keep this cheap

Should I think about rebuilding the supercharger? I'm not talking machine work. I'm thinking of bearings and stuff. I'm keeping the stock pulley.

the series 3 heads have larger valves. Cam is the same. Shouldnt be a problem really. Series 3 has stronger internals. Rebuild the supercharger only if it makes noise, probably around 100k it will need a new coupler and rotor bearings.