Best big block exhaust manifolds?

[pishta]

Besides the angel wing maniolds from the max wedge cars, what were the best production exhaust manifolds for the B/RB motor. Im going to use them on my next project (another 451 '65 Cuda) and heard the "normal" looking max wedge's fit without a hitch, but the things are more rare than a moped on nitrous...I need a few recommendations. My kit says Magnum's will fit, but arent there like a few different magnum manifolds out there? Maybe a few casting numbers for the swap meet black book. Thanks

[ehostler]

Only two different Magnum/HP manifold styles. One style for the B-bodies and one slightly different style for the E-bodies.

[lenweiler]

We've used the '72,3,4 drivers side in a '69 Cuda with just a touch of grinding. They're similar to the '67-70's.

[George G. Leverette]

I really don't know what a Magnum exhaust manifold is by definition but try these numbers: 2806900-2806974-2843992-2863409-2899970-2899879-3671595-3751068-375107137510713769207. These are the numbers I used when trying to locate a set of manifolds to fit the 440 in a 73 Duster, they were used on C,B and E-body cars from the late sixties through roughly 1974. Several of the manifolds fit the 440 A-body so there should be no problem in any other line.

[Dart]

HP manifolds on a 451 stroker? Sort of like putting a cork in your backside if you ask me. A good set of headers would be a much better chioce.

[pishta]

Dart, you think I didnt think of that? We are talking LIMITED space on the sides, and NO ONE makes a header for this app. The only header that I think may work is a Pro-Parts header or a Headman Hustler fenderwell that sweeps up from the ports and then plunges down through the top of the fender, and those are made for 67 and up with the wider fenders. Guys are running 10.9's with Manifolds in the Shootout series and they are in 3400 lb E's with "stock" 440's. My A weighs 2900, so Ill still be "competitive" with good manifolds....

[Dart]

What car are you talking about here?

[pishta]

check my first post.

[6 packin]

Them cars pre 66 A body's are a nightmare! Good luck!

[Dart]

I would be willing to be that a set of shorty headers would fit your application.

[Dart]

How about these:

http://www.sandersonheaders.com/pagesbypartnum/dd2.htm

[George G. Leverette]

Are headers really the answer with todays 91 octane max in California, headers will "actually produce" only about 10-15 horse power over good manufolds. Treating the manifolds to a good coating inside and out will probally reduce it more. Forget that crappy comparsion in Mopar Muscle, it was ran without pipes at least 18' from the ends of the exhaust which would cause too much turbulance to measure acturately. Can someone produce a valid comparsion on headers vs exhaust manifolds on the same car???????

[pishta]

Nice try Dart, but no Cigar! As you can see Im talkin NO clearance on a downswept design. Granted this is with a power box and I got a manual in there now, but the proximity of the box to the block is unchanged.

[pishta]

Hey George, I got an OLD data sheet that has a stock 340 and then the same with Hooker fenderwell headers (good ones too) it picked up:
14@2100
8 @ 2500
6 @ 3000
7 @ 3500
8 @ 4000
7 @ 4500
5 @ 5000
3 @ 5500
2 @ 5800

That is kinda weak considering what a hassle it is to install, dont you think? Of course later mods would help but this is a good baseline for all you "bolt on" guys to consider. Test was on a '67 340 with the good manifolds and full exhaust.

[451Mopar]

I have done a fairly good comparison with my very mild (almost stock) 383. This comparison had the stock magnum manifolds on the car with a new 2.5" dual exhaust system all the way out the back with dynomax super turbo mufflers.

The car setup like this only ran 15.5 -15.6 ET's (remember this is a #4,000 car @ 6,000 ft altitude with 3.23:1 gears and a 2,000 stall converter.)
Changing to headers the car ran 14.9-15.1. Overall it reduced ET's by about 0.5-0.6 seconds! I'm not sure why such a large difference, but that was my results. Also, the passenger exhaust manifold had the heat control valve removed when the manifolds were on the car, so I know there was no unusual restriction in the manifolds.

As for what will fit a '64 A-body? I haven't a clue, that sure looks tight! Maybe a tubular K-member with rack-and-pinion steering will make room for some headers?

[DartGT66]

There are not even good underchassis headers for small blocks in an old A-body, and there is no way you can stuff underchassis headers there with a BB, no matter how "shorties" they are. The engine compartment in those cars is about 1.5" narrower than in '67 & newer cars, and there is not much choice for them either. I have used non hp "log" style manifolds with an iron headed B-block in a '65 Valiant, but still had to modify the outlet angle on the drivers side + the engine was moved two inches forward (don't ask me why, maybe because the 727 didn't fit the trans tunnel?) I have seen Hooker fenderwells slightly modified fit, don't know if the modification is really necessary though. And of course the least expensive way is to build your own! It isnät as difficutl as it may seem at first, but still takes some time

[George G. Leverette]

Thanks for the comparsion numbers, they look like others conducted in a controlled enviornment. the track test would be affected by weather conditions. At Los Angeles County Raceway in Palmdale, Ca you see dial ins based on time of day and weather conditions. The cooler it gets the faster you go 80 Degrees F at this altitude seems to be the breaking point where the times will start to change. I saw one test where the 340 HP manifolds with extrude honing and coating inside flowed as well or better than headers, "but" always check the magazine advertisers to see which product always win.