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Please help guys. Taking a SB 350/350 car to a 427/400 car. I have heard driveshaft are same length minus of course the 400 yolks, also was told they are different lengths, was told crossmember are different, then they are the same. Was told you didn't need adapter plates as SB auto and 4 spd cars. Looks to me like just bolt up trans mount to crossmember. Any help would be great!
Not really sure what your asking here. Yes a big block will fit into your car. No I haven't heard of a different crossmember. 4 speed are part of the frame, auto bolt out. What gear box are you running?? What front springs to support the weight?
The only difference in crossmembers is between auto and manual transmissions. There are differences in U joints across the C3 lines. These are also related to Auto or manual transmissions. This is the list for the entire U joints selection. Halfshaft 1963-1979 all 1350 Halshaft 1980-1981 automatic 1330 Halshaft 1980-1981 4 speed 1350 Halfshaft 1982 1350 Driveshaft 1963-1967 all 1310 Driveshaft 1968-1970 4 speed 1310 Driveshaft 1968-1970 auto 1330 Driveshaft 1971-1979 all 1330 Driveshaft 1980-1982 rear u-joint 1310 Driveshaft 1980-1981 4 speed front 1330 Driveshaft 1980-1981 auto front 1310 Driveshaft 1982 front 1310
As for the SB to BB in a corvette, the main changes were the following. BB has the biggest 27" radiator in the C3, the exhaust is different, they would have the HD diff with caps instead of U bolt straps and they had different cooling reservoirs. Now the engines would not use the same accessory brackets or mounting either, and with the corvette you really have to watch pulley selection because the BB sits right over the front crossmember.
you can get away with small block diff and u-joints. just don't try to do wheelies.
The BB's and SB's shared the same differential assembly. Correct me if I'm wrong, but I believe the fabled L88 BB C3 race cars ran with a pretty much stock C3 IRS rear suspension; i.e. stock differential, half axles, etc. I think they could get away with this because running on a hight speed track (Le Mans, Daytona) was much less stressing to the IRS than drag racing.
It's just me, but if I were putting a BB in a C3, it'd have aluminum heads. Once again, my opinion, an all iron BB is a pretty piggy engine for a C3. Aluminum heads, aluminm intake manifold, aluminum water pump gets the BB down to the weight that closely approximates an all iron SB.
Last edited by 68/70Vette; Jul 17, 2020 at 04:24 PM.
The BB's and SB's shared the same differential assembly. Correct me if I'm wrong, but I believe the fabled L88 BB C3 race cars ran with a pretty much stock C3 IRS rear suspension; i.e. stock differential, half axles, etc. I think they could get away with this because running on a hight speed track (Le Mans, Daytona) was much less stressing to the IRS than drag racing.
It's just me, but if I were putting a BB in a C3, it'd have aluminum heads. Once again, my opinion, an all iron BB is a pretty piggy engine for a C3. Aluminum heads, aluminm intake manifold, aluminum water pump gets the BB down to the weight that closely approximates an all iron SB.
The difference between the diffs was U joint U bolt straps versus U joint caps for the BB. The cap diffs may have also been used in LT1s, but I don't know for sure.
The difference between the diffs was U joint U bolt straps versus U joint caps for the BB. The cap diffs may have also been used in LT1s, but I don't know for sure.
zz is an aluminum head engine, but everybody wants their nose an inch lower anyway, so do the big block on the stock springs. if too low, you have another project for another day.
I think the rear sway bar was added stock for BBs. The cross member part for the radiator was also different but I don't think this matters at all. It is a way of telling if someone did a conversion like your doing though.
I appreciate the convo guys. I swapped SB to BB springs and have the rear sway bar as well. Any idea on the trans mount? I have heard I dont need to use the trans mount brackets, just the mount to the crossmember?
I appreciate the convo guys. I swapped SB to BB springs and have the rear sway bar as well. Any idea on the trans mount? I have heard I dont need to use the trans mount brackets, just the mount to the crossmember?
auto or manual? The manual uses the brackets. The auto has a removable frame crossmember the mount bolts to.
If doing engine swap only, leave trans mounts be. SB and BB sit on same mounts and put bell housing flange in the same place. So trans is in the same place.
I swapped engine/trans 350/350 combo over to 427/400 combo. All I want to know is if the trans mount just sits on top of the crossmember? I don't need those brackets anymore right?
looks like 400 trans mount is 6 inches back from 350-manual mount. driveshaft spline and length also different. this article is for chevelles, but discusses the trans lengths in detail. http://www.superchevy.com/how-to/609...-swapping-tech
69 SB to BB
