I am cleaning up a 56 special 322 for my brothers 55 roadmaster and need some help. I'm switching the stock two barrel for a weiand dual four I picked up. Has any one had any sucess with this? I was thinking about running holley 390 four barrels with adaptors. Are there any differences between the 55 and 56? The motor is complete (pwr strng, gen, exh manifolds, startr, trans). I heard that the two barrel is low compression? How low? Upon tearing it apart the bores look good, I was thinking of just doing a cosmetic rebuild, (paint, bolts, gaskets, timing chain, and maybe a cam and head job). Is it worth the money trying to build up a "little nailhead", has anyone had any good results or suggestions? Was planning on a little cam, head porting, headers, elec. fuel pump (anyone know of a finned block off plate?) and fan, ignition. It's still a small motor for such a big car, should I just look for a 425, an overdrive, and toss the torq tube :grin: Does the 425 have the same mounts? Need to make the buick master the road again! Sorry so long, the site's awesome. Any help will be greatly appreciated, thank you.
Just wanted to clarify my intentions. I'm not looking to build a high rpm 322. I just want it to run whell with the dual fours. The roadmaster used to run pretty well with the stock 322 four. Are the 56 special heads different from the four barrel ones, or will a switch to high compression pistons fix it? I'd like to not dissassemble the shortblock. Are kb pistons available for the 322? Looking at the steering and master cylinder, headers would be a pain, can the exhaust manifolds be extrude honed? What about removing what appears to be some kind of choke? It's gotta hurt flow. Does anyone make mild cams? Any horror stories about adjustable pushrods with reground cams or do they work well in a low rpm situation? How are those roller rockers I heard about coming? PLEASE HELP!!!
I would call Postons, in Alabama. They have nailhead cams. I would think that Edelbrock (or Carter AFB's) would work best on a dual quad setup. No fuel bowl clearance issues, like Holley's. I also like the Edelbrock's tune-ability, and appearance. I dunno about roller rockers on a nailhead, but they DO sound like a good idea, considering the frictional horsepower loss inherent in the stock rocker/pushrod setup. I want a set for my 264! ('55 Special) And, I don't think too radical of a cam is a good idea, with a nailhead, for the same reasons--valvetrain geometry. A little more than stock is all you need. Too much valve overlap, and it will be a dog off the line (although, a Dynaflow's slippage might help in this situation) and the one thing you need with a "big" car, in my opinion, is good bottom-end torque! Dual Quads are WAY COOL!
Thanks for responding. I read in an old thread here about some roller rockers coming out but I think they're for big blocks (maybe they'll work?). I was thinking of holleys for the dual quad because they have a smaller flow rating. The smallest I've seen for a carter or edelbrock in 500cfm. Hopefully someone will respond who has done it before I'd hate to spend money and time building an unproven combination that'll fall on it's face. I hear a highperformance nailhead is tricky to build. I think I remember reading that the 401 nailhead built by street rodder didn't match the factory horsepower, (they never tell the results on the net, I'll have to look through my archives). If someone out there has info on a big block 401/425 swap into a 322 car I'd like to know if the motor mounts are the same. Thanks, Kevin Gastaldi
Kevin The 56 322 has higher compression than the 55's but a 56 Special 2 brl motor (8.9 to one) may not have higher compression than a 55 4 brl motor. If the 56 Special was a stick the compression was only7.6 to one. The 56 322 has bigger exhaust valves and more open combustion chamber with a longer duration cam than a 55. Don't use the 55 distributor in the 56 motor it will fit but the metal on the gear isn't compatable with the 56 cam gear. You can use a set of 401/425 rockers to get a small increase in valve lift. The 56 dual exhaust manifolds flow more than the 55's also. 53 to 56 Nailhead manifolds are interchangeable. You will need to change the water cross over manifold and front timming cover as the 56 has radiator hoses on the passenger side
Thank you very much for your info Judd it is much appreciated. I think I can live with 8.9 to 1 compression (came with the dynaflow still attatched) for a mild build-up, I haven't taken the shortblock apart and don't really want to. I couldn't find a machine shop in Miami that would rebuild a nailhead. Has anyone out there built up a 322 with a cam and other mods? I would love to hear what works and doesn't. Thanks, Kevin
Thanks Judd. I looked in the buick specialties inc. catalog and saw that the pistons they sell for 55 series 50,60,&70 are for all series of 56. I think the compression was with thick and thin gaskets? Would I have to change the pushrods to use the 401/425 rockers? Thanks again, Kevin
Kevin My 56 shop manual suppliment says 56 pistons have bigger dome than 55 pistons and larger valve relief for more clearance on bigger cam. Not sure about push rods but plan on a set of 401 rockers for my 56 so I'll find out. My 56 has glass packs and I get credited for having a mild cam at cruise nights all the time but it's stock.
