Quick question! Just got a 41 Buick and I have a nailhead that is supposed to be a runner. Wondering if the nailhead bell housings are the same as the fireball 8?
Depends on what you mean by “the bell housing”. The bell housings, as a component, are very different in the area where they attach to the engine block. The area that mates to the transmission case, however, may be the same…..but Here is where it gets a bit complicated. GM, and Buick in particular, starting about 1937, used 2 different manual transmissions….one for the ‘smaller’ engines, such as all the 248 and a heavier duty model for the 320 cubic inch, both of which were straight eights. Theses transmission looked the same at a casual glance, but differed in actual size and strength. They can be identified by the tin top cover, 5 bolts on the smaller unit and 6 bolts on the larger. They also differ in the bolt pattern, which is similar, but the 6 bolt unit has more distance between top bolts and bottom bolts. Also, it is worth knowing that the 5 bolt trans is kinda ‘weak’. The 6 bolt trans is much stronger. When the Buick V8 was introduced in 1953 Super and Roadmaster models it was 322 cubic inchs and if equipped with manual trans, it was the 6 bolt cover unit. The 1953 Special series was the last straight 8 and was fitted with the 5 bolt trans. Now, in 1954 all Buicks were V8s, but the Special was a 264 cu in and the senior models were 322s. The 264 was 5 bolt, the 322 was six bolt if fitted with manual trans. The back of the blocks, to the best of my knowledge, were the same on V8s thru ‘56 models. Somewhere after ‘56 the block to bell housing bolt pattern changed. In summary, your options depend on what year nailhead you have and if it has the stick shift parts (flywheel and bell housing) it was built with. Also, what Series is your 1941 Buick. The Specials and Supers had the 248 engine, 5 bolt trans…..Roadmasters were 320 engines and 6 bolt trans. Ray
I believe it’s a 56 322 so I’m hoping I’ll have a 6 bolt trans I’ll check in the morning. I’m just hoping I can bolt it up snd re drill the flywheel or get it all to work together. Or I’ll put a Chevy 3 speed with an overdrive snd slap a open drive rear in it.
Ray has sound advice., and is a wealth of knowledge on Buicks. I'm getting ready to put a later nailhead in a 40, and opting for a later tranny and an open rear by using a 58 Edsel axle and GM truck arms. Mine is a super and has the weak 5 bolt. Not sure what is meant by "re-drilling" the flywheel, and could create balance issues with the engine. Changing to an open rear is a complicated issue in these cars. The frame design is not conducive to leaf springs. The original design relied on the torque tube to counter axle wrap. Options to install an open rear are parallel 4 link, triangulated 4 link, or GM truck arms. I choose the latter for ease of modifications required. Other considerations are either the original coil springs or coil-over shocks.
Basically if I can’t get the nailhead to mate to the stock 3 speed I’m going to take my 49 olds rearend set up out and bolt it in with a 55 Chevy 3 speed with an OD attached to the nailhead. It will all plop in for the most part.
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