379M-V6 GMC !

[M123KT-450]

I would like to adapt the 500CFM holley to my GMC Big Block V-6.
engine has the small little 2bbl on it now is there an adaptor for the big 500cfm 2bbl ?

edit:
Dose anybody offer an adaptor to go from the small 2bbl to the big 2bbl carb ?

Mike

 

[chevyinlinesix]

I'm pretty sure I know what you are talking about, wait until later today and I will snap a picture of my adapter and tell me if that is the one you are looking for.

 

[83GMCK2500]

How's this Mike? http://www.6066gmcguy.org/holley.htm

 

[83GMCK2500]

I think the links are dead on his site, but if I'm reading it right, it's this adapter kit from Mr. Gasket: Model Number: 1937

 

[chevyinlinesix]

This adapts a 2 barrel 500 CFM Holley to a 2 barrel Rochester carburetor that has one small bore and one large bore, like half of a Quadrajet. There was no adapter available that did this, so I had to make one, and no I'm not a machinist. Lets just say it took a lot of drilling and filing.

 

[M123KT-450]

This adapts a 2 barrel 500 CFM Holley to a 2 barrel Rochester carburetor that has one small bore and one large bore, like half of a Quadrajet. There was no adapter available that did this, so I had to make one, and no I'm not a machinist. Lets just say it took a lot of drilling and filing.

I need the one for the 4 studded even square up to the big offset one. . .
It lists a few 305's but mines the 379M. . .

Mike

My intake looks like this:

 

[Pepperidge]

http://www.jegs.com/i/Mr.+Gasket/720/1937/10002/-1

 

[M123KT-450]

thanks much man very helpful. :thumbsup: :thumbsup:

Mike

 

[M123KT-450]

1 more question guys. . .
The 60-66 GMC site lists the 379-V6 as having 190hp@3,600rpm n 260tq@1600rpm.
But when my 379M-V6 was rebuilt it dynoed 175hp@3,400rpm n 388tq@1800rpm.

Why the difference ?

The guys i have talked to about my Big V6 all say do the 500 2bbl it runs out better.

dose this mean i might gain some power ?
or
dose it mean it'll just whined up quicker ?

do you think going to the much bigger CFM 2bbl will effect my power numbers much ?


Mike

 

[chevyinlinesix]

379M-V6, I assume it's 379 cubic inches. I think the 500 CFM would only help it gain power overall. Normally putting on a bigger carburetor looses you some bottom end power, but in this case, seen as how you have 379 cubic inches I think you'll be fine.

Now I don't know very much about these big block V-6's (other than I really like them) but an engine is an engine, and all require a certain amount of air. The Holley can probably be tuned better than the factory carburetor, if done right I'm willing to bet power gains across the board, how much I don't really know.

 

[M123KT-450]

379M-V6, I assume it's 379 cubic inches. I think the 500 CFM would only help it gain power overall. Normally putting on a bigger carburetor looses you some bottom end power, but in this case, seen as how you have 379 cubic inches I think you'll be fine.

Now I don't know very much about these big block V-6's (other than I really like them) but an engine is an engine, and all require a certain amount of air. The Holley can probably be tuned better than the factory carburetor, if done right I'm willing to bet power gains across the board, how much I don't really know.

Yea its 379 CID its a huge V-6 in rather not so big truck. . .
1962 GMC its a regular Cab with 7ft bed, 1-1/4ton dually axles and 19.5 wheels n tires.
379M-V6, SM-420 4spd, locking rear with 5.13 gears 34" 14ply M/T tires on 19.5 wheels. its a short wide truck that go any place you put it.

Truck really has the sawed off shot gun effect, and i don't want to lose power tho it don't need to gain but i'm not complaining if it dose gain some numbers :thumbsup:

Mike