TBI/Emissions swap question..rfmaster?

[manimal]

I have my '89 Suburban 2500 454 TBI,th400 2wd. I bought a 1985 Chevy crewcab 1t dually. No engine,was 454 carb.... I will be using the 'burb engine in the dually. I would like to use the TBI, but have questions.
1) My Suburban has a catalytic converter...do I have to use it? The dually does/did NOT have one.
2) The dually has dual exhaust...will this make the TBI run lean?...will it be legal to run duals with TBI?
Thanks

[Firebirdjones]

Ooo, living in California is one of the worst when it comes to engine swaps. I've went through this before with California.

What they'll want is everything emissions related to the year and model vehicle the engine is coming from, installed into the receiving vehicle.

Your dually likely never had a cat converter due to it's GVW. I know in the 70's anything over about 8,000 GVW was exempt from cat converters, and that rule may have been used up into the 80's. Unfortunately some smog stations don't recognize this and insist on having one. Lack of knowledge on their part. Went through that on my 79 1 ton.

Anyway, as far as the engine swap goes you'll likely need to transfer everything to the dually to be smog legal in Cali. Luckily you have the donor vehicle complete.

Your biggest obstical will be the exhaust. If you run dual exhaust and they gripe about cats, that's probably where the biggest red flag will be.

When I did my swap ( a 96 LT1/4L60 from a vette,,,into a 82 Jeep Scrambler) California wanted the complete exhaust system from the donor car to be California smog legal. I laughed but they didn't think it was funny

Like I'm supposed to make a 96 vette exhaust fit a 4x4 Jeep Scrambler? Get real. Needless to say the jeep was registered in Nevada to to avoid all that sillyness.

Not sure how hard it will be to graft a suburban exhaust to a dually but if they are still as picky as they were a few years ago, this is one thing that will come up. Unless you know someone that knows someone

[manimal]

Thanks Firebirdjones! I think I will end up calling the ref today to see. if nothing else, I will but the carb back on and sell the TBI set-up.

[rfmaster]

Originally Posted by manimal

I have my '89 Suburban 2500 454 TBI,th400 2wd. I bought a 1985 Chevy crewcab 1t dually. No engine,was 454 carb.... I will be using the 'burb engine in the dually. I would like to use the TBI, but have questions.
1) My Suburban has a catalytic converter...do I have to use it? The dually does/did NOT have one.
2) The dually has dual exhaust...will this make the TBI run lean?...will it be legal to run duals with TBI?
Thanks

Basic CA rule for emission compliant swaps - take everything from donor and install in the target vehicle (in this case newer truck to older truck is OK). The 85 dually will have to comply with '89 emission rules which are not too bad.

1) You'll have to use a single CAT from 89 burban in your 85 crew. PO may have removed CATs from a dually and sold them off. Newer high flow CATs offer very little back pressure over original GM bricks so that there little performance loss. Use 2-1/2 (or 3") after cat exhaust - it should be adequate for a stock 454 as it will live under 4500 RPM.

2) You'll have to use a single exhaust (2 into single CAT) unless you can find documentation that GM shipped CA certified dual (dual CAT) exhaust system in 89 3500 series truck or burban. I have never seen one - sorry! I do not know if CA SMOG referee will allow dual exhaust even if equipped with dual CAT's - this is a gray area. Dual CAT exhaust will not make TBI lean - O2 will keep AFR in close loop and maintain 14.7:1 under most conditions.

What ever you do have plenty of patience and will work out!

//RF

[JCampbell]

Originally Posted by Firebirdjones

Anyway, as far as the engine swap goes you'll likely need to transfer everything to the dually to be smog legal in Cali. Luckily you have the donor vehicle complete.

Yep. The ruling factor is going to be the donor vehicle. You have to have all the emissions equipment from the donor installed and in proper working order.

As far as it being "hard" to do...it all depends on the inspector. A buddy of mine swapped a newer 3.0l Toyota into his 4Runner and had no issues getting it signed off. He said the Inspector was really cool. Knew his stuff, knew what my buddy was trying to do, had him fix/adjust a few minor things, but other than that, it was no big deal. I've heard of other guys who must have run into into Inspector Hardass because they nitpick every detail.

Luck of the draw, I guess.

[manimal]

Thanks guys!...