Holley 750 (vacuum) or 650 double pumper or Thermoquad?

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dustoff440

dustoff440

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The Holley 3310-2 has the metering plate instead of the metering block. I also have a new Proform carb body for it. Am I wasting my time trying to drill the plate jet holes instead of buying a metering block with screw in jets. I have a buddy who has a large assortment of smaller drill bits. I'm on a really tight budget here. LOL

Also I was told that these bodies flow about 830 cfm and I'm thinking it might be too big for my set up even with a stiff secondary diaphram spring
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Here's the quick stats on my set up:

Completely stock 1992 360 Magnum with the exception of 340 exhaust manifolds, Hughes valve springs, MP Dizzy w/ orange box, cam 496/512lift 276/286 duration 110 centerline, 3.91 sure grip, 3000 stall converter, reverse manual valve body.

The other options are an off the shelf 650 double pumper and a Thermoquad off of a 76 400 cid also bone stock. I only have enough cash to make one a runner can't afford to build and experiment with all three.

Can't afford to experiment with all three, can afford to refurbish only one... would appreciate advice on which one to start with.....I'm really leaning towards the Thermoquad.
 
since you only got one shot..my 2 cents

3310-2 is a pretty old holley...might want to check on the throttle shafts to see if they are loose..also a rear metering block would be better then drilling the plate...

thermoquad...parts availability....????

holley 650 dp has my vote if it is a good carb....

since you say u got only one shot...choose the carb that is in the best shape...
 
Yea you're probably right I forgot about the no jets or metering rods unless you rob old thermoquads and the secondary throttle bushings on the 750 are'nt really that great. I'm not sure that my skills and tools are good enough to correctly do the shaft bushings on the 750. The 650 falls in line with the cfm calculation formula. Now that I think about it I really only have a slightly warmed over motor. I was thinking though that the 650 dp might bog it??????
 
Everybody has their own likes and dislikes.I would go for the thermoquad if it is in good shape.Make sure the bowl isnt cracked.Brass floats-in my opinion,are a must.Kit and floats will set you back 40.00.They can be onery to dial in on your engine,but they are very consistant
 
I went out and gave the 750 base plate a really good exam. The secondary throttle shafts bushings definitely are going to have to be replaced. So I'm going to post the Proform carb body in the for sale or trade section. Not only that a new metering block
is like 60 bucks or more plus a kit etc etc. It has added up too fast. I got the 650 from a friend who bought it new and I know that it has only 10,000 miles or so. He pulled it to put on a Holley Projection. All it needs is a thorough cleaning and a kit which I think I can get for about 40 bucks. This will be the shortest quickest cheapest route to a running carb as I just priced a tq kit and floats and it was quite a bit more than just a holley kit. Plus I have lots of spare holley bits from the old 750 that I can use. I'm not totally discounting the TQ as I have had great sucess with them in the past but right now I'm rolling up change to get enough money to keep working on the Dart. Every penny counts. LOL
 
another thing about the 650 dp...later on you can upgrade the to a proform main body and new base plate...
 
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