Carb info

steve99_old · December 10, 2007 at 1:32 PM

I need to fit a carb to my 65 k ,,,does anyone have info on a good replacement and also has anyone fitted a 715 holley and if so what did you think

Thanks

66gtk · December 10, 2007 at 3:10 PM

715 is too much carb, even with a high rise manifold. Try a 600 CFM carb with a stock HiPo.

zray · December 11, 2007 at 8:23 AM

<BLOCKQUOTE id=quote>quote:<hr height=1 noshade id=quote>

715 is too much carb, even with a high rise manifold. Try a 600 CFM carb with a stock HiPo.

this is the conventional wisdom, especially with the stock iron manifold. However, I use the 715 w/ the vintage Shelby aluminum manifold with very good results. Engine has stock internals with the exception of roller rocker arms. When I had the carb restored (by Pony Carbs) several years ago, I did ask them to do what they could to reduce or eliminate the hesitation off idle. I don't know exactly what they did, but the result was phenomenal.

I used an Autolite Hi-Po carb for several years on the same engine with predictable results. The Autolite carb worked better off idle, but not by much, while the Holley carb was far superior above 4000 rpm. A night and day type difference. We all know the kick of the Hi-Po cam above 3500 rpm, the bigger carb takes advantage of the Hi-Po cam very well. So I have to conclude that the Holley 715, with the right adjustments and manifold, will work on any Hi-Po 289 without problems.

Z. Ray

66gtk · December 11, 2007 at 8:46 AM

I think it also may depend on automatic or manual tranny. The 715 was too much carb on my Dad's GT350H automatic with the stock Cobra high-rise. Runs much better now with a smaller carb. I think the Shelby autos started with the 715, but Shelby quickly realized the cars worked better with a smaller carb and then used their own version of the Autolite 4100 for the Automatics. Shelby's also had headers, which also should improve things.

marv · December 11, 2007 at 9:35 AM

Yes, that is true that the Shelby Autos used the HiPo Auto Carb- they tried a handful with the 715 and found it didn't work. BTW, '67 Shelbys had Exhaust Manifolds.

C6ZZKGT · December 11, 2007 at 12:43 PM Official Post

I tried to use a 715 with a Hipo C4 combo 25 years ago and the only way that it was reasonably effective was with a high stall converter.

-Fred-

zray · December 11, 2007 at 1:38 PM

any one care to conjecture what Pony Carbs did to my Holley 715 to minimize the off-idle bog that characterizes using a too-big carb?

BTW, I had a GT-350H with the Holley & automatic trans. As others have noted, the automatic seems to make the problem worse.

Z. Ray

Edited by - zrayrichter on 12/11/2007 13:40:54

steve99_old · December 12, 2007 at 4:47 AM

My car is a manual so your saying that the problem will still be there in a manual with the holley ? I like the idea of the 715 dont know why ,,but my car does have shelby type extractors and alloy intake rest is hi po

zray · December 12, 2007 at 7:50 AM

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My car is a manual so your saying that the problem will still be there in a manual with the holley ? I like the idea of the 715 dont know why ,,but my car does have shelby type extractors and alloy intake rest is hi po

if you have access to someone that really knows carbs, and can tweak the Holley a bit, it will work fine. Otherwise you will have an off idle bog or hesitation using the Holley 715 on a basically stock 289.

Z. Ray

289kford · December 12, 2007 at 12:34 PM

My kar had a holley 715 when I got it, I thought it was too big and switched to a 650 but transfered the center feed bowls so it still had the 'look'. It ran much better with the 650. That lasted a few years till I called PONY carb and got a reworked 4100. I think it runs just as good if not better, and less screwing around with it.

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