Help with decision

[Patrick B.]

Re: Help with decision

A single Quadrajet was probably the best driving carb ever on a Corvette and the 3 Holley setup was the least dependable and most complex. The bling isn't worth the hassle. Be thankful you can have originality and dependability at the same time with a nice looking aluminum manifold to boot.

[Mark E.]

Re: Help with decision

Be thankful you can have originality and dependability at the same time with a nice looking aluminum manifold to boot.

I agree. Originality is good, plus a nice Q-Jet will generally out perform a tri-power anyway. But I do understand the bling factor.

If the intake is aluminum it's from an L36, not a 454 like Gregory stated.

[Domenic T.]

Re: Help with decision

Rich,
Years ago I swapped my tri power (67) with a 69 and the aluminum manifold was a square port. Waaaay back then a swap for a undamaged manifold and carbs was the thing to do. Oh well.

Dom

[Gregory H.]

Re: Help with decision

The intake is actually a cast iron 6263753 from a LS5 454. The carburetor is a Holley Presumably a R6239A (I really don't know). Carb 1.jpgCarb 2.jpg

[Gregory H.]

Re: Help with decision

Thanks. Appreciate your advice.

[Michael J.]

Re: Help with decision

The intake is actually a cast iron 6263753 from a LS5 454. The carburetor is a Holley Presumably a R6239A (I really don't know). [ATTACH=CONFIG]65409[/ATTACH][ATTACH=CONFIG]65410[/ATTACH]

There are numbers and letters stamped on the front of the air horn of the Holley, you can check those and it will tell you the variety and maybe the date of the carb.

[Gregory H.]

Re: Help with decision

72 454 cast iron intake... Holley 4bbl carb. Carb 1.jpgCarb 2.jpg Intake Image Cast#.jpg

Thank you for your feedback

[Mark E.]

Re: Help with decision

It looks like it shows PN 6263753 which Dr. Google says is a '72 big block spread bore intake.

But what's odd is the carburetor. I've never seen a dual-feed, spread bore Holley. Whether 650 or 850 CFM, mechanical or vacuum secondaries- everyone Holley spread bore I've encountered has the Q-Jet style fuel inlet in the front.

Has anyone seen another dual-feed spread bore Holley?

Gregory- Things you might address:

- Rubber fuel lines under pressure (between the pump and carb.) are dangerous. Consider replacing with a steel line as equipped by the factory.

- The throttle cable sleeve is damaged/missing.

- I suspect the choke was removed and PCV intake relocated because they interfered with the aftermarket dual feed fuel line.

If you keep the intake, consider using a Q-Jet, or maybe a spread bore Holley with a Q-Jet style fuel inlet. That way you can use the stock all-steel fuel line, have a working choke and reroute the PCV pipes back to stock.

[Joe L.]

Re: Help with decision

If it's a 390, then a tripower was not original. If originality is a requirement then you'll need to get a correct cast iron intake and Holley.





Rich

Rich------


1968-69 L-36 used an aluminum manifold with Rochester Q-Jet.

[Joe L.]

Re: Help with decision

It looks like it shows PN 6263753 which Dr. Google says is a '72 big block spread bore intake.

But what's odd is the carburetor. I've never seen a dual-feed, spread bore Holley. Whether 650 or 850 CFM, mechanical or vacuum secondaries- everyone Holley spread bore I've encountered has the Q-Jet style fuel inlet in the front.

Has anyone seen another dual-feed spread bore Holley?

Gregory- Things you might address:

- Rubber fuel lines under pressure (between the pump and carb.) are dangerous. Consider replacing with a steel line as equipped by the factory.

- The throttle cable sleeve is damaged/missing.

- I suspect the choke was removed and PCV intake relocated because they interfered with the aftermarket dual feed fuel line.

If you keep the intake, consider using a Q-Jet, or maybe a spread bore Holley with a Q-Jet style fuel inlet. That way you can use the stock all-steel fuel line, have a working choke and reroute the PCV pipes back to stock.

Mark------

The carburetor pictured is not a spreadbore Holley. Therefore, since it's used with a spreadbore manifold, there must be an adapter used between the carb and manifold.

[Mark E.]

Re: Help with decision

Mark------
The carburetor pictured is not a spreadbore Holley. Therefore, since it's used with a spreadbore manifold, there must be an adapter used between the carb and manifold.

Duh- of course; and obvious now that you say it, Joe. I think I can make out an adapter in the photos. I'm surprised the hood closes with it. And I'm surprised the low profile air cleaner fits over the Holley.

Gregory,

You'll find the car runs a lot better and more efficiently with a properly set up Q-Jet featuring a choke and sans adapter. Or as you mentioned, go bling and get an original looking L-68 set up.

[Dan A.]

Re: Help with decision

I can see why that car caught your eye! Like the others I think you would be very happy with a properly set up Quadrajet.

[Douglas L.]

Re: Help with decision

My 68 L36 with the correct 3919849 intake and 7028209 carb runs very well. once dialed in about as close to EFI as any carb engine i've ever owned. Obviously, given the choice I'd rather have a L68 engine for desirability and looks but I kind of doubt the tri-power set-up would run as cleanly as the Q-jet.

[Gregory H.]

Re: Help with decision

Now I get it!!! This way I can have my take and eat it too... another friend just suggested the same thing. And the light bulb just went off. My wife is always struggling with ideas for Xmas and birthday presents. Now I have a list. At 64 it seems that it takes me a little longer some times! Duh...

Gregory, I think I understand......albeit a bit confused at the slightly contradictory thoughts regarding originality....

If it's a 390, then a tripower was not original. If originality is a requirement then you'll need to get a correct cast iron intake and Holley.

I think what you're also contemplating though as a option is making a upgrade to enhance the appearance of the engine appearing like a 400hp when you open the hood. It's the wow factor and probably and has nothing to do with keeping it 100% original, as noted above, am I correct? Since you have the wrong intake and carb on there now, you could take it all off and part it out to help offset the cost of your upgrade change or finding correct parts.

However, the cost of a oval port intake and 3 Holley carbs, fuel lines, linkages, etc may be a bit shocking to you. Along with that unique triangular air cleaner.

While you're having fun with your tripower "recreation/clones", you could always continue the hunt for a correctly dated cast iron intake and carb and when found you could store it on a shelf for a potential downgrade later.

Then if you ever want to go the Flight judging route a top end aspiration swap would be in order.

Rich

[Jim H.]

Re: Help with decision

Greg,

I considered putting a tripower set up on my NOM 66 recently. Crane and others offers the intake, carbs, and air cleaner complete for about $4500 and it is a very tasty looking unit. Before I committed, however, I surfed this technical discussion board and the archives and was surprised to find much knowledgeable opinion and detailed analysis indicating the tripower was inferior to a well set up 4bbl. Given this and the fairly expensive cost of the tripower, I elected to stay w/a 4bbl. Had the tripower been original to my car (427/390) I would have obtained one, but where it is not original, is difficult to tune correctly, and is a step backward in the performance department, I saw nothing to recommend it and passed.