okay so here is my issue. i put a cat back exhaust system on my car with my 307, and i would like to continue to use this system. the only difference is the y-pipe because of the different exhaust manifolds. can i fabricate my olds y-pipe to work with the chevy manifolds? or am i absolutely wasting my time?
okay so here is my issue. i put a cat back exhaust system on my car with my 307, and i would like to continue to use this system. the only difference is the y-pipe because of the different exhaust manifolds. can i fabricate my olds y-pipe to work with the chevy manifolds? or am i absolutely wasting my time?
Your Olds doesn't have a Y-pipe. It has a crossover pipe from the driver's side to passenger's side manifolds then a separate pipe from the passenger side manifold to the converter.
The bigger question is that if you are installing a 327 Chebby, you're already not smog compliant, so why keep the converter? Just run true duals. If you need to pass a smog test where you live, the 327 will not pass.
Of course, the even bigger question is, why go through all the trouble just for 20 more cu in??????
well im going to take the cat out. and its a decently built motor, and this is just a right now fix. because im taking a week off of work to do the swap, and it has to be done before aug. 30th because thats when i start school.
Buick Grand National wheels and Chevrolet Monte Carlo SS wheels on an Oldsmobile Cutlass. I like it. I say run the 307 while you are going to school and building the engine you want to put in it. Once schools out and the engine is ready then do it.
The exhaust will probably work with a Chevy Y pipe and cat, but since you plan on removing the cat it wouldn't matter anyway. You'll have to fab something to attach the the intermediate pipe behind the cat. A quick look at the Wagner exhaust parts on rockauto.com shows that 83 up LG4 Montes and Y motor 307s share the same intermediate pipe. So it should work depending on what you installed back there.
But if you're considering swapping the stock 307 Olds for a Chevy, the exhaust is the least of your worries. Have you thought through everything else? Does your transmission have a dual bolt pattern to fit the Chevy? Motor mounts? front engine accessories, fuel line relocation, A/C parts if you're trying to keep that, etc, etc. It's a straightforward swap, but you need a whole lot more than just a motor and a Y pipe. You probably thought all this through, but just in case I thought I would mention it.
thank you on the compliments and advise, but i have already thought these things out. the motor is also built and ready to go in. and the reason i need the y-pipe is the differences in olds and chevy manifolds. true duals would be awesome because headers would be better with the combo i have, but money and time is the issue. i really do not want to wait untill the semester is over to put my engine in :|. this is so frustrating
Dude, I'll talk all day long about your car if you want. I'm just not sure what your question is that hasn't been answered. As mentioned above, the Olds Y pipe/crossover pipe will not work. You're going to need SBC exhaust manifolds, y pipe, cat or test pipe, to connect to your existing cat back system. Keep in mind that the G-body SBC Y pipe crosses under the motor between the drop in the oil pan and the frame. It's a tight fit, so you must have an oil pan that is compatible. Many aftermarket oil pans will not allow enough room for the pipe.
Another option is to go with a header setup like Edelbrock which includes headers and y pipe, but again you must have sufficient oil pan clearance, and you must provide your own EFE valve. The cheapest option would be to get manifolds, Y pipe, and cat from a donor car in the junkyard, but don't expect much performance there. Don't forget you'll need all the bits and pieces like hangers for the cat and the EFE valve that goes between the right manifold and the Y pipe, all the bolts if salvageable. You can buy a new Y pipe if you want. Rock Auto has them in stock, but you still need manifolds and stuff.
So, if you have a stock G-body oil pan you can try to find a donor car to get everything. Otherwise the header and duals route might be your next cheapest option. I'm curious, how stock is the 327? The 4.56 gears would seem like a complete mismatch and pretty unstreetable.
Feel free to ask or re-ask if you still have a specific question that is not being answered.
okay, thanks. and my 327 is a large journal 350 block with a 327 crank. the block is .030 over (331) and has 10.5:1 flat top pistons. it has a flat tappet edelbrock torker plus camshaft with 1.6 ratio rockers and fuelie heads. i have an edelbrock performer intake manifold with a rochester quadrajet. and a completely re done factory HEI dist. thats about it right now :shock:
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I say run the 307 while you are going to school and building the engine you want to put in it. Once schools out and the engine is ready then do it.
