600 cfm on a V6?

Still haven't found a decent, cheap 390, but I have 2 near new 600 cfm carbs, a Holley and an Edelbrock. Has anyone used that big a carb with the V6 or is it more than the motor can handle, I'm using an Offy manifold. This would be a tempory instalation untill I find a 390.

 

toooooo big.

 

I am a self proclaimed Holley guru. I tried to tune a holley 600 on my dauntless. Way too big. I finally found a 390 and found it to be too small, I finally settled with a 450. Definatelty the best holley carb for this little motor. If you do get a 390 be careful, there are several different ones. There is one designed specifically for 4 cylinder motors and it wont run right on your application. Hope this helps

 

Thanks guys

 

67CJ5

I could use a Holley guru. I have a 390 and a 450 that I would like to rebuild for my project. However, the primary throttle shaft in the 450 is pretty sloppy. I have seen kits with a reamer and bushing to tighten things up, but the kit costs almost as the carb.

Do you know of a source for reasonably priced places to have throttle plates repaired or cheap bushings and reamers?

JC

 

Thanks for the info.

JC

 

i run a carter afb 600 cfm 4bbl carb on my v-6 on a 2 bbl intake and it works great but it does run a little rich so i need to calibrate it to run more effecient. but other than running a little rich i have no complaints about it at all.

 

The big plus to both of these carbs is that they run vac secondaries. This means that the secondaries won't flow more than the engine needs. The big thing I'v found with the V6 is the importance of the size of the primary side. Spread bore designs seem to work the best due to the small primary side bores. This keeps the pulses crisp in the venturi, allowing for good low end throttle response. I've run all the carbs mentioned in this post. The Holly 600n was the worst. I had good luck with the Edlebrock and the 450 Economaster. I'm curently running a Q Jet, and have found it to be the best of the bunch.

 

Sorry i never got back to you, i didnt revisit this thread. i have sent them in mostly, but the last few I did myself at work. Alot of good sources out there

 

11/32" valve guide liners for small block Chev heads works great on Quadrajets. Might check and see if it'll work on a Holley. Any local engine machine shop should be able to install them. Then just have to hone to fit your shaft. Done it a couple of times and works great on Q-jets. Nickmil.

 

Thanks Nick, sounds like a good thing to look into. I sure do like the creative engineering one can encounter on this site.

Jim