Goldhawg

iTrader: (7)

Probably going to go headers, but wondered what is the best flowing set of factory manifolds that would fit nicely in a a GM a-body 1971. I'm half wondering that with the amazing power one can get out of the LS motors, maybe just stick with manifolds as they are much less of a long term hassle than headers. What kind of power can one get with just manifolds? If I was going that route, would it make sense to get a cam or is a cam only worth combined with headers?

For now I don't have anything; just planning. But assume 6.0 or 6.2 LS engine (LY6 or L92).

Thx for your thoughts.

bczee

iTrader: (12)

I had used 4th gen F-Body before I switched to Edelbrock swap headers.

Fit pertty good.. no area that made contact.. would suggest you re-clock the Driver side O2 sensor inboard some to help.

Most will say that you are leaving a lot on the table if you don't go Long Tube Headers.. but.... depending what what your plans are for engine mod's and output.. you should be ok with Manifolds...

If you stay with Mnifold, I would suggest you keep that in mind if you do other mods and bolt ons. Going overboard with Cam that doesn match up the Exhaust and Intake would just not be good idea and might hurt you expected Output.

Goldhawg

iTrader: (7)

Thx...here is at least one data point that works. Are there other manifolds that work? Of all, are any known to flow better?

If anyone went manifolds vice headers, what cam route did you go?

Thx

chuckd71

iTrader: (23)

I don't have an answer for that but it might be easier to get the cam you want now as switching from manifolds to headers later would probably be easier than switching a cam.

2nd Gen Fl 'bird

iTrader: (13)

Don't know your HP goal but, the ZO6 platform seems to get 400-425 from the factory. no reason you can't get that. Check out Jan. '05 in Car Craft Magazine. They do a manifold vs. header comparison, pretty interesting read. The more radical your set up is, the gap gets waaay bigger on HP from mani's to headers. On a mild motor, $1000.00 for 15 HP gain from exhaust not worth it. Of course this is IMHO.

garys 68

iTrader: (1)

What he said. I picked up a pair of GTO manifolds (same as in article) for my 72 cutlass. I've heard they wont fit, but for $30, it's worth a shot.
http://www.carcraft.com/techarticles...est/index.html

Goldhawg

iTrader: (7)

When do you expect to do a test fit? Inquiring minds want to know!

badtomatoes

I would also like to know. I am doing a 6.0/T56 swap into my 66 Chevelle. If this goes like any of my other projects, I'll spend more test fitting manifolds than I would buying a set of swap headers.

1970

Gary, Saint Louis,
Update the rest of us when you know how well they fit.
1970 Chevelle

garys 68

iTrader: (1)

I'm waiting on parts this week, but we had this little ice/snow storm (maybe you heard about it) that's delaying things.
Probably try a test fit later this week.
Btw, my build thread is below. I'm using 1" setback plates (similar to edelbrock), tall narrow motor mounts, and unusually tall 307 chevelle frame mounts. So I'll post here and on my build thread when I find out.
https://ls1tech.com/forums/conversio...442-build.html

2nd Gen Fl 'bird

iTrader: (13)

I think alot of people set a motor in with the first set of parts they can find and deem everything "works good" or "doesn't work". Some people want a direct bolt in on a conversion, ain't gonna happen. Those engine bays in A bodys are "cavernous". Easy to move the motor around to make things fit. By all means keep us posted on your findings.

Goldhawg

iTrader: (7)

Anybody seen a set of the new camaro manifolds in an a-body?? These are pretty reasonable:
http://cgi.ebay.com/ebaymotors/LS3-L...Q5fAccessories

SLP also has a complete set w/cats for $359 on ebay as well. I want cats so if they fit it might be a good deal.

garys 68

iTrader: (1)

Those look like they should clearn the crossmember without issues. But no chance they'll clear my z bar.

Andy1

Though not applicable to your particular swap, I'm going with the LS6 cast headers on my LS1 since they can support a 400HP stock application (and that would be my max goal).

Andy1

rojs234

iTrader: (5)

You're kidding...it snowed at your house? I hope the GTO's work..I've got a set I need to sell, LOL Ron

garys 68

iTrader: (1)

I've got those on the LQ9 in my 68 corvette. When I did some rough measurements, they looked like they'll hit the crossmember. They do clear any GM Z bar mount location though.

SUPERIORMOTORSPORTS

G8 manifold work great in any swap.

64skylarkconvls1

I'm in the middle of my swap right now. I have an 02 Camaro LS1 6 speed setting in the my 64 Skylark (same as 66 Chevelle). The stock Camaro manifolds fit with one problem; the oxygen sensor on the drivers side needs to be fitted elsewhere. I'll drill and tap a new hole for it unless I go with some long tube headers. I did need a tiny bit of grinding on the PS flange. The original cat pipes hook up with plenty of clearance. Made my own motor mounts.

I am using the Camaro column though so I can't say for sure if it would be an issue with the original column, I don't think so though.

Without seeing the article mentioned, was there much difference in the GTO manifolds verses the Camaro manifolds I'm using? I guess one question is how much hp gains can be expected from long tube headers over stock GTO or Camaro manifolds?

bczee

iTrader: (12)

Yeah, that is what I did.. (post #2) "would suggest you re-clock the Driver side O2 sensor inboard some to help"

I can take a picture of it if you needed to see it. I am not using them right now. I've put Edelbrock Headers on now, and the manifold are in storage.

John McGraw

I tried the LS2 Corvette, C5 ZO6, G8 and GTO manifolds, since I had them all on the shelf in the shop. None of them worked. The GTO manifold turned out and hit the frame, while both the ZO6 and LS2 Corvette manifolds hit the crossmember. The G8 Manifold would go on, but the pipe flange was hard on the frame when installed. I was sure that a set of F body manifolds would clear, but finally just ended up putting a set of Edelbrock stainless headers on it.


Regards, John McGraw