This guide is intended to acquaint you with various intake manifolds for Small Block Chevys (SBC) that accept three two-barrel carburetors.  This intake system has been a hot-rodding staple since the '50s.  Two barrel carburetors were plentiful and cheap; four barrel carburetors were "new technology" and therefore expensive and rare in the early '50's.  Aftermarket manifolds were cast to allow multiple two-barrel carbs to be installed on many different engine families, and the car makers noticed the general appeal of the system.  Soon many engines were supplied with Original Equipment Manufacturer (OEM) three two-barrel systems.  The manufacturers also applied trendy marketing names.  In general, GM used the term "Tri-Power"; while Mopar used "Six-Pack" or simply " 6"; Ford called it "6V" with the "V" short for "Venturi".

Chevrolet never released a Tri-Power manifold for the Small Block as a production item.  There were some aluminum prototypes made by Winters Foundry; Smokey Yunick tested at least one small-block manifold designed to accept Holley carbs.  He was disappointed in the power produced, and no further work was done on that system.  Chevrolet did produce Tri-Power systems for the big blocks; the 348 "W" engine got a system with Rochester carbs, while the 427 Mark IV engine from '67 to '69 could be ordered with triple Holleys.

Since there are no Genuine GM Tri-Power manifolds for the Small Block Chevy other than super-rare prototypes; if you want Tri-Power you're going to have to look to the aftermarket.  Fortunately, several manifolds are still available new, and two companies are still making 3X2 carb sets.  Holley is still producing replacement carbs for the Mopar 340 and 440 engines; although they have discontinued the ones for the Corvette.  Barry Grant/Demon is selling 3X2 systems for various engines; at this point they are only selling the complete "kit" which comes with a manifold, carbs, air cleaners, and linkage.

(Sorry--I have NO CONTROL over the size of the photos)

Can you see the vacuum pods denoting the Holley carbs?
Photo supplied by Schurkey

This is a list of all the aftermarket Tri-Power manifolds for SBC that I am aware of.  If you know of others, PLEASE contact me--especially if you have photos that I can include in this Guide.

Demon/Barry Grant "Six Shooter"
Offenhauser 3287
Offenhauser 3558
Offenhauser 5254
Offenhauser 5893 (Base) 5899 (Top Plate) and 5900 (Linkage kit)
Edelbrock 5419 (unpolished) and 54191 (polished)
Fenton (no part number available to me)


Photo supplied by johnnyfishbone

Weiand (no part number available to me)

Photo supplied by hotrodcoupe32

There is yet another tri-power manifold (a "new" example sold on eBay in late September, '08) which fits Holley carburetors.  I contacted the seller asking for permission to host the photos used in the auction, and also asking for the manufacturer's name.  The seller claimed he didn't know who made it; and did not give permission to include the photos.  The only identification on the manifold that I know about is "Z3x2-SBC-01" cast into the manifold near the distributor opening.  I can only say that it sounds like the Chinese are knocking-off 3X2 manifolds now, since this manifold from any of the established name brands would be big news.  If and when I get additional information about this manifold, I'll add it here.

You might also want to look at Cross-ram manifolds for SBC--A primer
 GM Small Block 350 Engine Families--A Primer and HEI Ignitions--A primer

If this guide has been helpful, please click the "Yes" box below.  If you have suggestions for improvement, please contact me through the "My Messages" feature of eBay by clicking on my user name above and then on "Contact Member". 

Entire contents copyright (C) 2007, 2008  Camino3X2     Feel free to LINK to this Guide in your auctions.