I would like to put a 4-speed transmission behind a 62/63 401 Nailhead engine to replace the crapped-out Dynaflow. Wasn't the 4-speed transmission a factory option for those years? What Buick bellhousing should I be looking for? Does it have a specific casting number? What about aftermarket? Do I have to get and install a pilot bushing in the back of the crankshaft, and if so, what is a source? What clutch, flywheel and transmission will work? It doesn't have to be 100% correct/authentic so long as it all goes together and will work well behind the 401. 'Appreciate any information from someone who may have already been down this road.
Southfork, Be wary of replacing the Dynaflow with a manual trans or a Super Turbine 400. The 62-63 401 uses a unique crankshaft that is not going to accept the ST 400 converter snout. The four speed parts are really built from"unobtainium" and if you do find them, they are expensive. Rod and Custom magazine did an article a couple of issues back about trans swaps, and they gave the names of some companies that had parts. The most interesting was Bendtsen's who made a 700-R4 adapter for the 63 401. That kit costs $700.00, but maybe the most cost effective in the long run! HTH Tim McCluskey
Hey Tim, I thought I read somebody was making a collar to center the TH400 snout into the dynaflow crank? Would that be possible, or am I in left-field (again)
Nailhead to Chevy tranny adapters: http://transmissionadapters.com/53-66_nailhead.htm I thought about this myself, but decided to go with a Switch Pitch 400.
Adam your playing left field just fine. Carmen is listed in Nailhead Vendor section he has the item, and many more Nailhead goodies. I'm with Jim and would go with the SP400 just my .02
Hi Guys! The SP 400 Swap is not a slam dunk on the 63 and earlier 401's. The ring gear for the starter is on the converter on a dynaflow, the SP 400 uses a seperate flex plate. 63 starter is different, crankshaft is different and bolt pattern is nailhead specific. I'm sure that parts are available to do the swap, but it is important to stress that this is NOT a BOLT IN! Repairing the Dynaflow is going to be expensive, but upgrading to a more modern transmission is going to be expensive as well. I would think about how the vehicle is going to be used before I would decide on a transmission. If you are going racing, the SP 400 makes sense. If you are cruising around town, going to car shows or using it as a daily driver, the overdrive automatic is the only way to go! The four speed would be fun, but requires all the correct original parts or the availablity ofaftermarket or specially fabricated parts to make it work. Makes finding a decent used Dynaflow sound like an option!! HTH, Tim McCluskey
Try posting your question on the Yahoo Nailhead site at: http://autos.groups.yahoo.com/group/NailHeadBuick/ A similar question came up regarding the install of a ST400 behind a 364...I imagine you would need to perform similar mods. Anyway, here is the response from one of the board members: >>the 64-66 401-425 400 trans bolts right to the 364 block, you need a 64-66 401-425 starter and flexplate. You will need to drill a hole in the block to mount the starter, rebalance the flexplate for the 364 engine, grind the lip off the back of the crank and make a bushing(or buy one from Carmen Faso) that fits in the end of the crank to center the flexplate and hold the end of the convertor. Carmens # is 716-693-4090.<< Bellhousings for the 65-66's are very difficult to find. They have a unique clutch 'fork' used only those two years.... But I believe earlier bellhousings are more plentiful. There were even some 'adapter' bellhousings made by aftermarket companies...it shouldn't be too incredibly difficult to find one that will work for you. Post on the Yahoo site....and let us know what you find out.
I think your best bet before you get too confused on the issue is call "Carmen." He is revered by everyone I have ever met that has talked to him. A real nailhead expert to the nth degree, and nice guy too. Heck, his name is already in this subject thread twice!
4-speed nailhead :Brow: south fork, I just got done doing the 4 speed swap on my 63 wildcat. Let me start with the fact that it takes a lot of custom fabrication. As you've already read, the parts are extremly hard to come by. I did mine with alot of custom fabrication. The 63 crankshaft does have the same bolt pattern as later nailheads but the center register is larger. I bought a new flywheel from t/a performance and had a machine shop bore the center of the flywheel to match the same size as the dynaflow flex plate. Next, I used a starter from a 64-66 nailhead. I had to make a pilot bearing adapter out of aluminum to press fit in the end of the crank with a new pilot bearing inside of the aluminum adapter.(I have a metal lathe)but any machine shop can do the same relatively cheaply. I also welded the clutch pedal and pivot arm from a 63-73 chevy truck to the top of the stock buick brake pedal assembly. The truck pedal attaches to a shaft inside a tube with bushings inside. (I welded the tube to the buick brake assembly)Then I made my own linkages and attached them to a z-bar from a 70's chevy truck with one of the arms repositioned so that when you push on the pedal it pulls on a link attached to the clutch fork( pulling on the clutch fork from behind) A lot of work huh? also I had to shorten the clutch pedal about 2.5 inches. The bellhousing is an old transdapt unit. You can still find them on e-bay or maybe someone here on v8 buick can find one for you. I have a lot more info for you or anyone else interested. Just e- mail me at sagosti1@aol.com. I love my 63 wildcat 4-speed. I have surprized quite a few of the ricer imports with the big bad buick.
Yeah, I'll bet you've surprized a few ricers! It does sound like a lot of work.. but a 4 speed behind 401 or 425 just appeals to me. I'm going to see if i can round up all the parts, but if i can't, I can always go to an automatic as a fallback, and be satisfied with a 3 speed behind an early Nailhead project.... You see, I've got this old rod in the backyard that I got from an old man who built it in 1957. It originally had a flathead Ford V8 and 39 Ford toploader transmission. Later the guy swapped the flathead for an early Olds engine, and in about 196o or 61, he swapped the Olds for a 1955 or 56 Nailhead. He tells me all kinds of cool stories about his youth and racing that Nailhead-powered rod in So Cal, --- still with the 39 Ford tranny and Ford torque tube rear end. I cant' wait to get that going again. And if i can't come up with a 401/4-speed combination, 'guess I'll have to settle for the vintage equivalent.
Gosh, why not stick with the 39 trans? Classic rods are all of the rage, and not only would the restoration of a old-school hotrod be cool but it would be worth more too! Plus, all you have to do is make the flywheel/starter setup work with the 401.
401 4-speed :beer southfork, That old rod sounds bitchen. Go for it. As for the tremendous torque of the nailhead 401, don't expect that 39 trans and banjo rearend to take it for very long. Granted the light weight of the rod and open dif will probably just send the right rear up in smoke, but hope it does'nt hook up or it's el- explodo for the dif. If you really dig the nostalgia stuff like I do, just take it easy. Like I mentioned earlier there was a lot of adapters made in the 50's and 60's and I think offy might still make an adapter for the 39 trans. If not, then hunt it down on e-bay. Also the 39 trans has no syncro's so it's double clutch up and down. Cool nontheless! As for settling for an automatic, real rods have three pedals! Automatics are like a rubber with a hole in it. If you have any more trans swap questions, feel free to e-mail me. Good Luck!
