OFFY TRIPLE QUESTION FOR FLAT LOG HEAD

[jacks66mustang]

I am rebuilding my 200 out of my 66 stang. I have a C9 flat log head and purchased the Offy adapter for it (large bore carb with two smaller on outside.) Anyone know if I will have enough hood clearance to make this work? Carter carb on C9 head looks really tall! Also besides milling the head to 50CC's and zero decking the block anything else I need to know about installing a C9 head? Thanks

 

[jahearne]

I plan on doing the same thing to my '66 Ranchero. Couldn't tell you about the carb height. I'm planning on using Holley 1904 carbs that have a low profile, but the problem is that center carb; the flange is too big for the 1904s and other 1 barrel Holleys that I have found so far. The Offy kit for earlier heads has 3 flanges that are all the same from what I can tell, which would look much better with all 3 matching carbs especially the glass bowled 1904s! It would also simplify things dealing with 1 brand instead of 2 different carburetors.

I think the best way to go is CF center carb and two Holley 1920s on the outside with the later head because of the larger intake log volume and valve sizes, but I'd much rather have 3 matching carbs. 1920s look closer in height to the CF carbs.

For modifying the head, the best advice I found was in the Falcon Performance Handbook.

Anybody use the Offy 3v kit for the later heads? Any suggestions for getting 3 matching carbs bolted on?

Thanks,
John

 

[Gene 64 2dr]

I bought a Offy manifold that I'm going to use on my large flat log head. You can use three autolite 1100 carbs on the manifold. You just can't use the large bore, 1 3/4" ones on the two outside mounts because the holes are too small and the throutle plates will not open all the way.

Gene

 

[Gene 64 2dr]

One other thing about the newer manifold is the outer two carb mounts are about 1/2" lower so that the three carbs won't line up as far as their height.

Gene

 

[jahearne]

Thanks Gene. Right, the 1100 come in both sizes.

I just ordered Ford Carburetor Guide. According to Pony Carburetors, the 1100s have problems from the factory; their $299.50 re-engineered carbs fix that. Too steep for my pocket book.

Jack66mustang,
The Falcon Performance guide has a good picture of what other mods need to be done to adapt the Offy kit. You have to bore two extra holes and tap 4 studs on each.

John

 

[CobraSix]

As far as hood clearance, I went with the 1100s on my 65 when I had the offy. It was a very very tight fit on the front carb that required a filter that was shorter then 1" tall from the venturi of the carb. To my knowledge, the 1100s are the shortest carb you can find easily.

Slade

 

[mugsy]

I put a 250 head from a '76 Granada on my '65. Its the flat log style (I can't remember the casting code). Here is what I found:

1) The temp sending units were different. The '76 unit had a smaller "post" for the electrical connection, so the stock '65 wire would just fall off. Then the pipe threads on the outside of the units are different. The '65 unit was smaller (1/4" NPT I think) versus the 3/8" NPT (I think)for the '76 head (they might also be 3/8" and 1/2"). Anyway, the threads are different size. I bought an adapter and used the '65 sending unit.

2) The T-stat housing have different outlet diameters. I had to use the '65 house after I had smoothed, sanded and polished the '76 housing. The upper rad hose on the Granada was larger diameter.

3) I went with Weber 34 ICT for the end carbs. These are typcially used in VWs. I bought individual filters from Weber for these carbs. They seemed to not interfere with the hood.

4) I am running a Carter YF as the center carb and used only the center carb to get it running. I put the old granada air filter on it after I cut the base so it looks like an open element assembly. It clears the hood with about 1/2" clearance.