Well here is my first post outside the new member section. I have a stock '85 5.0 Qjet GP. The build plan is a 96-99 350 L31 from a truck with a cam, intake manifold, 4 barrel etc. The question is will the same headers that fit my stock 5.0 fit the L31 vortec? Because my 5.0 only has 95k original miles, does not smoke and runs really well. The factory Y pipe is ratted out. I'm wrapping up a K5 Jimmy build also and will probalby only do the L31 engine build next year. So in the interim I was debating doing the complete exhaust for the L31 so I can at least drive the car and the exhaust would be ready to accept the L31.
L31 Vortec - Headers
- Thread starter FL85GrandPrix
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Headers. Not manifolds. Based on what you said, regular G body SBC headers will fit the future L31 engine swap.
Yep, I had mid 70's iron heads on my car before. Then when I built another motor with vortec heads I used the same full length headers. They fit pretty much identical, I think I might have gained a little spark plug clearance as well.
Good deal guys. My car is bone stock and in excellent condition. Bought it from the original owner a few weeks ago. Being I am hot and heavy wrapping up my '89 K5 project this winter (yeah, FL winter means cool enough to do car work for longer than 15 minutes and not die of heat stroke) I'm doing a one-over on the GP so it's a reliable driver and not just a garage ornament. Now That I got into the GP, there is a side of me that says I should just do the full exhaust, suspension work etc and then do the motor last. The stock 305 Qjet runs perfect, does not smoke, and only has 95k miles on it. I have service records for it and the trans, and the entire car, going back to 1985. So I think I could buy some time and get the thing derivable, with some cheap mods and then next winter do the L31. But the idea is any "mods" will be with the L31 carb setup in mind. So instead of putting money into the stock exhaust setup so it's derivable... just do the headers back and be done.
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Is you L31 complete or in parts. If its complete you could just run the motor as is with only a intake change and a upgrade to a 4 pin HEI. You will also need a electric fuel pump because the L31 is not drilled for a external fuel pump and if it is the stock roller cam does not have a fuel pump lobe. The stock vortec will make a lot of power even with out a cam upgrade its a cheap upgrade with the stock hyd roller cam and way better heads.
L31 is not even purchased yet. For exhaust I'm looking at the Full length headers and the Flowmaster system. I am also thinking maybe I want to do a F body type Flowmaster system. Single 3-3.5" pipe into a suitcase muffler with dual outlets. Haven't spent enough time looking and thinking on the exhaust. It's important to have a good Y-pipe or X pipe to balance everything out.
Consider the Jegs dual exhaust kit for our cars. It is incredibly good value for the money. The only downside is you cannot use your stock crossmember, but Jegs sells their own crossmember pretty cheap. You can even do some medications, like adding an H/X-Pipe or cutting the exhaust so it exits behind the rear tires instead of straight out the back. I've been very happy with mine.
http://www.jegs.com/i/JEGS/555/3055...lX4o20y7eePYXCTFVNUIdkt-yvBPrUjyGNhoCFpTw_wcB
http://www.jegs.com/i/JEGS+Performa...BvpKowhAsFEmtSJ3WZZfMay6jjVp8vyea_xoCc2zw_wcB
http://www.jegs.com/i/JEGS/555/3055...lX4o20y7eePYXCTFVNUIdkt-yvBPrUjyGNhoCFpTw_wcB
http://www.jegs.com/i/JEGS+Performa...BvpKowhAsFEmtSJ3WZZfMay6jjVp8vyea_xoCc2zw_wcB
This is what I'm looking for!!! Put a set of full length headers and a good Y-pipe in front of it. Done.
http://www.jegs.com/i/PYPES/958/SGG12S/10002/-1
http://www.jegs.com/i/PYPES/958/SGG12S/10002/-1
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