I am thinking about renewing the exhaust piping on my '71 skylark custom with a rebuilt 350-2. (.020 over, comp cam 92-202-4) I will keep the single exhaust setup with stock headers and would like to add a classic 40 flowmaster to it. Which piping would be the best, considering performance and sound/drone? 2,5 or 3 inch?
I know you said you want to keep your single exhaust, but if your upgrading, I would SERIOUSLY consider duals while still keeping your iron manifolds. Its not much more money, and you'll pick up a few h.p. seeing you have a cam and your .020 over.
Duals, with an H or X pipe... you spent the money for the cam, let the engine breath better... muffler choice will be about the sound you want, not necessarily any more power (one vs the other). As for Flowmasters, I've only heard one or two that don't drone... my personal preference is for straight through designs.
If you end up using Gardner, they will make you a system that is built for your car. You can also upsize the pipe to their performance system. I would call them and talk to Eric on what he can provide. It's not cheap, but it literally will bolt right in. Not like these other "kits" that require work for them to fit. Plus, you get a cool beer glass with purchase LOL
Yes, 2.5" is perfect, you'll still have clearance where there should be verses 3" which can get kinda tight. You don't have to use an "H" or "X" pipe, I had used an "H" pipe for years, but it really gets in the way if you ever need to pull the transmission down the road, as far as a performance gain from an "H" or "X" pipe, eh, some say yes, some no, I say it effects the sound or tone more than anything. Those crossover pipes are suppose to increase low end torque a bit, but the Buick 350 does not lack torque down low in the small block world. Check TA performance for a manifold back 2.5" system, its excellent quality, aluminized, and mandrel bends, its probably less money than a Gardner system. The Gardner systems ARE nice, but if your doing a summer driver, verses a garage queen, TA is the way to go Check page 137 in TA's catalog, its sounds like they're for header back, BUT they have down pipes if your using manifolds.
Do T/A’s 2 1/2” system, no X or H pipe, and Walker 17748 mufflers. You’ll be good for the power you make now and for the next 200 hp. Patrick
2.5" for sure, 3" once you exceed 500hp in a big block. Mufflers, as already said, are your choice for sound. I have a 2.5" system with an X-pipe and Dynomax 17749 mufflers on my Buick and while they sound good, if you're looking for something a little louder then this setup wouldn't be your first choice. I have Flowmaster 50 series on my big block El Camino and they are perfect for that car. No drone like the previous mufflers that were on the car. Also as already indicated, all other Flowmasters I have experience with have a nasty drone.
I got a 2-1/2" system from T/A. Like said above, aluminized, mandrel bends, and fit well. They are the only ones I could find that had down pipes for Buick to use stock manifolds. I used Dynomax 17749 mufflers. You can get Pypes or Flowmaster kits cheaper on line, but still have to find down pipes. I didn't use the hangers that came from T/A though, as they are universal muffler shop rubber strap jobs. I ordered OEM style hangers from In Line Tube. You might want to consider getting the slip joints welded as the clamps don't seem to completely seal them. And that may be the case with all kits. There's a member here that sells several brands of kits as well as T/A.
Ok, here is the point: I live in Germany and it is quite pricy to get a shipment like that here to germany. The exhaust system has to be done because it is rusty and leaky. Due to my job I do get 3-4 times a year to the states so I try to get the most important parts on those trips. I get a lot of piping for a good price over here.. but you have to customize it.. So my thougt was to get the muffler in the US and get the Rest over here.. The car is a summer only weekender.. not a daily driver at all.
Well, that puts a different spin on it. Are there exhaust shops there? You might be better off to have a system bent up there at a shop. Wouldn't be mandrel bends, but probably be fine. I think GM used 2-1/4" front pipes and 2" tail pipes and no mandrel bends. Complete duals with all 2-1/4" would let it breath better than it ever has.
Hi Olli - have you checked with Mike&Franks? They should have what you need - probably done some Skylarks / GS before... Worth a call and no hazzle with oversea shipping, customs etc.
IF your going to keep the single exhaust I would go 2 1/2 ". With dual's all you'll need is 2"-2 1/4".
Go big or go home. If you are going to do dual exhaust, make it 2 1/2" with Walker 17749 mufflers. No need for X or H pipe.
I didn’t see your location; that does change things. Have an exhaust shop bend 2 1/2” pipe and put Walker 17748s or 17749s in it. I ran non-mandrel bent like that on a ‘68 with a 455 and headers; it still ran mid 13s in the quarter. You may have to get someone in the states to send you specifications of the bends. Patrick
Tripple7, A little advise concerning mufflers and drone, especially on vehicles with rear gear ratios in the 2:56-3:08 range- you will most probably experience drone with a Flowmaster 40 series muffler, probably experience it with a straight-through muffler, and least likely to experience it with a turbo style muffler such as a Dynomax Super Turbo. If you are set on the Flowmaster sound, a Super 50 or 70 series is a safer bet as they are designed to suppress drone while still allowing the famous FM sound, albeit a good deal quieter. Straight- thru mufflers do have a tendency to drone, with some being better than others (MagnaFlow comes to mind), and Turbo's do the best job suppressing drone. Those ratios I mentioned usually put cruising RPM in the 1800-2300 range- right where drone occurs. At your HP level, you would be wise to follow the advise of some of the above posters and go with a 2.25" system, especially since nobody make a 2.5" downtube that bolts up to your stock manifold.
