Opinions on 650 Spreadbore

[Deryl]

I've got a deal lined up on a new Holley 650 spreadbore for $200.00. I can get it for that price because the store does not have the box or anything, just the carb. I need to replace my worn out Quadrajet and the price is definately right. It's going on a .30 over 350 with a mild cam and Performer intake. Someone told me it would require frequent adjustment. Anybody have an opinion about this carb?

[Mike C]

They are a Holley carb. You should have no more troubles than any other Holley. I have run square bores, spread bores, vac secondary and mechanical. Some for lots of miles. BUT, I now have JET Q-jets on both of my trucks, and they do run about $350 for the stage II, but that's what I would do. And I have bought a bunch of Holleys in the past and swear by them if max performance is your goal. Otherwise, go for the Q-jet.

[cduster]

My expirience with Hollys has been :

1) They need frequent idle mixture adjustment
2) In 4wd trucks, if they get to an extreme angle, the floats run over
3) One little backfire and the power valve is shot

If you get it, get the re-usable gaskets for the float bowls and programming plates. You will save yourself a lot of trouble with them. If you use the regular gaskets, coat them with vasiline so they don't stick, cause you will definately have to take them apart at some point. Stock up on power valves and different sizes of jets.
I put larger accelerator pumps and larger fuel squirters on mine, and it took care of some hesitation on my truck.

Although they do have their problems, when they are working, they are good carbs.

Dan

[doughby82]

if you dont mind the edelbrock 1406 or 1405 they run 200 bucks all day long and you get the box for what its worth

[Longhorn Man]

And a better street carb will be in that box.
*better as far as aftermarket carbs*

[jimfulco]

I had my worn out '72 Qjet rebuilt (including throttle shaft bushings) for around $120 by a local auto electric/carb shop. It's the OEM carb calibrated for the car & it runs like new again. Had a spread-bore 650 on it for a while & I don't miss it at all.

[Deryl]

Thanks for the input. I think I'm going to pass on the Holley and get the Edelbrock. Max performance is great, but reality is that it is more of a daily driver than a drag car.

[cduster]

good choice. I don't think you will be sorry for it.



Dan

[GMC JUNKIE TOO]

gonebad2 I have a 670 street avenger Im still playing with it but it has run good so far im just trying to get it set for my aplication.

[Deryl]

Another question. Is the squarebore 1405/1406 going to work on the Performer intake that the quadrajet is on or do I have to have a an intake specificaly for a squarebore?

[dwaite72lnghrn]

The 1405/1406 will bolt right on the small block performer. You don't need the adapter. If you went to the 1411 then you need the adapter. This according to the papers that come with the intake/carb. go with the 1406 it has the electric choke.