dmentzer

I would like to put 2.5" exhaust manifolds on my 66 small block. I have searched the archives and have not come up with a conclusive answer. I want to keep my alternator on the driver side with the same type mount. It looks like the 563 LH manifold that Paragon sells will work. Has anyone done this?
Thanks

GCD1962

Put on headers instead

Scott Marzahl

Headers will do little for the power curve. Like the LT-1 cam the L-79 cam was designed to work best with manifolds, and headers will cause the usual header headaches - heat, burned spark plug wires, radio interference (because you can't install the spark plug RFI shields).

See the attached thread and also link to the referenced thread on Dave McDufford's engine.

http://forums.corvetteforum.com/sho...5614&forum_id=4

(Too bad the good knowledge on this site has a life of less than a week!) Time spent searching the knowledge base should be useful to you, too.

Your best bet is to remove the heads and have them properly pocket ported and port matched. They should be throughly rebuilt with new valve guides and valves as required, then three angle seats ground.

While the heads are off you can check for bore taper/out of round to get and idea how much is left in the block. As long as you don't oil starve the bearings, they will last virtually forever.

The 2.5" manifolds will also be helpful, and they can be integrated with no problems.

With properly massaged heads peak power will be at or beyond the 6000 redline with the L-79 cam. With the LT-1 cam power keeps increasing all the way to 6500, so that's also an option.

Proper head rework/rebuild, 2.5" manifolds, and maybe even an LT-1 cam should fit within your $1500 budget if you do all the teardown and reassembly yourself, and all the major castings and appearance will still be original except the manifolds, which only an NCRS judge would notice are "not correct".

The WR four-speed and 3.36 axle is probably the best overall combination.

Duke

Hitch

The manifold that you want is the one that is used for AC 66 cars but if you just get the repop Left manifold you can make it work too. All you need is a "F" style header bracket and a generic upper alternator bracket and a NAPA 25-7550 belt. Make sure that your alternator is clocked to the right position as in this pic of my setup. I couldn't spring for the big bucks that most want for the correct L manifold when I was doing this. Another bit of information that most neglect is to port match their manifolds when installing them. Not a lot of hp but every bit helps. Sorry I don't have the numbers for the correct air 66 L manifold... Dave..

vark_wso

3846559 is LH '66/'67 exhaust manifold for all 327 engines except A.I.R. smog cars. It is a 2" manifold.

Hitch

Mark I think the number he's looking for is the one for a A/C 65.. That would be a 2.5" manifold with the alternator mount provision on the drivers side like what's needed for 66 wiring.. Dave..

JohnZ

The '64-'65 LH A/C 2.5" manifold is casting #3846563

dmentzer

Thanks John.