california stock exhaust

[chockblockjed]

anyone know the stock configuration of an exhaust system for an 81' C10 short bed with a 350 and standard transmission? i have to visit the CA DMV referee for my engine swap and want to make sure my exhaust is good to go, especially with all the new 2009 cat laws around here.

[78 Big10 454]

I'm not sure of your configuration, but I'd stop by a muffler shop and see if they can look it up for you. They use a manual that shows the stock exhaust set-ups for all vehicles originally equipped with cats. Worth a try.

[chockblockjed]

The muffler shop I use has two manuals with conflicting info, one says two cats and the other says one, ain't that a shocker. Hoping someone on here remembers their 81' before they started wrenching on it!
Thanks

[menace121978]

1 cat. if you look under your truck you should see where the frame rail on the drivers side was bent to fit the large old school cat in there between the tranny and frame. thats how my '78 and '85 k5 were. 1 cat... smog tube manifolds to a y-pipe to the cat out to a muffler.

[78 Big10 454]

Mine was set up the same exact way with one cat wying off to two mufflers/tailpipes. I subsequently changed over to two cats/mufflers in 1980 and have never had a problem with passing smog.

[chockblockjed]

Thanks! Confirmed y-pipe to one cat. I hope to go to duals as well, but since I have to visit the CA DMV referee for the engine swap and there are some stringent cat laws effective this year, I figure I would go stock for now. Thanks for the input!

[78 Big10 454]

We are at your service!

[menace121978]

[Navy Lalor]

dude i am in san diego and swapped out a for a 350 bored .60 over extreme comp cam forged pistons, posi rear 4:11 gears....650 holley carb..then headers straight to cherry bombs thats it ..wo cares california can suck my balls.....keep your stuff registered in another state

if your military

[AceX]

For those of us who aren't signed up though...

There aren't any new laws pertaining to cats or the quipment in general. They have been the same for a long time. You need the OEM equipment from the donor car/motor or an OEM equivlent. Thy will allow you to run newer style cats and such, but you are not allowed to eliminate any equipment from the system and the ref. knows how to check if its in working order, so don't try and slip past him either.

[staggerd86c-10]

lmao, its like the man kickin it to the man!

[staggerd86c-10]

in cali you guys cant run aftermarket straight thru high flow cats? damn that sucks.

[chockblockjed]

Its done for now. I went stock 2.5 with custom collectors and y pipe into 2.5 oem style cat into single 3" out the side. I get to visit the referee next month and get my sticker for a CA legal motor swap. I have been driving the truck for the past two weeks to work and really love it! It moves without effort and sounds great.

[longbedrick]

I had an '81 K5 Blazer that was all stock. The exhaust manifolds came together at a "Y" then exited through one cat-back and one exhaust pipe. my '76 1/2ton had true dual exhaust with no cat backs and only A.I.R. fittings on the exhaust manifolds. both were California vehicles

[Malo83]

Originally Posted by staggerd86c-10

in cali you guys cant run aftermarket straight thru high flow cats? damn that sucks.

I'm running a Magnaflow 3" High Flow cat on my 83 with no problems

[SSC's76]

Originally Posted by longbedrick

I had an '81 K5 Blazer that was all stock. The exhaust manifolds came together at a "Y" then exited through one cat-back and one exhaust pipe. my '76 1/2ton had true dual exhaust with no cat backs and only A.I.R. fittings on the exhaust manifolds. both were California vehicles

The 76 was probably a federal version regular leaded gasoline. Alot of the trucks around here were setup that way to. Anything with that good old unleaded only came with a cat. Needeless to say thats probably the 1st modification my old man did when we moved to colorado back in the early 80's. LOL.