Author Topic: Small and Big Block Chev Bellhousing bolt patterns..  (Read 595 times)

dutch

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Small and Big Block Chev Bellhousing bolt patterns..
« on: February 11, 2020, 03:23:22 PM »
Sort of a strange question I admit - but can anyone tell me if the block bellhousing bolt patterns are the same or different between small and big block castings?
I have a very well built engine stand and I would like to sell it to free up some space and also for lack of need for it, but I can't find anywhere that confirms the block bolt patterns are different or the same..
I've always played with small blocks and welded up this stand for ones I had, but the question "would the fixed standoffs also allow a big block to be bolted up to it" and I really had no certain idea.. 
I'm pretty sure they would, considering most all of the transmissions interchange between them from what I know - but in saying that I realized I was somewhat assuming (you know how that works) and would like to get some better assurance that is the case before I try and advertise it..
Thanks for any input or comments!
Randy 

Everett#2390

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Re: Small and Big Block Chev Bellhousing bolt patterns..
« Reply #1 on: February 11, 2020, 03:25:30 PM »
Yes, SBC & BBC bellhousing bolt patterns are the same dimensions.
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dutch

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Re: Small and Big Block Chev Bellhousing bolt patterns..
« Reply #2 on: February 11, 2020, 03:41:30 PM »
Thanks for the confirmation - I really thought so but...
Were there any outliers or exceptions through any and all generations?


z28z11

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Re: Small and Big Block Chev Bellhousing bolt patterns..
« Reply #3 on: February 12, 2020, 02:04:46 AM »
Thanks for the confirmation - I really thought so but...
Were there any outliers or exceptions through any and all generations?



Early L6 (216 and 235 engines) were different. V8 pattern lasted from '55 to '93, with the introduction of the 5 speed manual transmission. Trans patterns stretched from really early (my '49 has the same trans bolt pattern as Saginaw and Muncies) to '93 as well, although the two lower bolts of the trans are threaded into the trans, not the bellhousing, which continued for a good length of time on truck transmissions. You can bolt a Muncie to the '49 using nuts on the inside of the bellhousing for the two lower holes.

One bit of trans swap trivia - I bolted a '65 Muncie 4 spd in place of my '57 Bel Air's long tailshaft 3 speed (original non-synchro 1st gear) trans in '71. Used the original driveshaft with no mods, Input shafts are the same on all of them for length, the tooth count changed to a fine spline in '70 (and 400 output shaft diameter). Bolted the same long tailshaft '57 trans into my dad's '49 3100 3 window and hooked it to the column shifter using the same linkage from the '49, after pulling the old torque tube driveline out. You gotta love commonality/interchangeability among GM parts -

Regards,
Steve
1968 Z28 M21/U17 BRG/W
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06  1949 3100 5wd 235/6

dutch

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Re: Small and Big Block Chev Bellhousing bolt patterns..
« Reply #4 on: February 12, 2020, 11:20:16 PM »
The replies were much appreciated - Thanks!