Have any of you converted a small block cutlass to a 455? Could you post the necessary changes/headaches involved..(mounts, issues trans etc..) Do the engine mounts line up, or are different ones needed? What ones will work. Will it bolt up to a power glide or do I need a turbo 350? Maybe there is thread here you could steer me towards if you know of one. Thanks.

 

Are you talking about a 68 Cutlass? Im not sure what you would need to do but other people that do know need the year.

 

This has been covered here many, many times. The BBO and SBO are externally very similar. The primary external difference is the deck height. The motor mount attachments are in exactly the same place, the bellhousing bolt patterns are the same, the accessory brackets are the same (for the years where Olds built both BBO and SBO, anyway), etc. This is a bolt-in.

Do NOT get "455 motor mounts" unless you also get matching frame mounts. You don't really need them anyway. Until 1969, the BBO and SBO used the same part number motor and frame mounts. Note that most parts houses have this wrong. In any case your existing 350 mounts bolt directly to the 455.

As for the trans, NO Olds engine bolts to a Powerglide, which comes with a Chevy only bolt pattern. If, however, you're talking about the ST300 (Jetaway) two speed automatic used by Olds for 1964-69, then yes, it bolts up. Note that the Jetaway has exactly nothing in common with a Powerglide other than the gear ratios. No internal parts interchange.

 

Just finished my conversion. a 74 delta 88 -was 350 stock, now heavily modified 461. Spent hours modifying the bracketry from the 350 but all fit nicely and are a lot lighter then the 455 brackets.Chinese engine mounts SUCK. Re-use the old mounts if possible.Or buy a lot and match up ones that actually fit-good luck.Everything alse is easy.

 

Sorry, yes it is a 1968 Cutlass S.

 

Great info. I was pretty sure this was covered on another thread, but I am relatively new to this site. I'll figure out how to do a better search someday! LOL Thanks for the repeat of the info. I am amazed at what you folks know off the top of your head!
Yes, the trans is the Jetway trans. I honestly believed it was another name for the power glide. Thanks for the correction.

 

The 350 and 455 brackets are identical and carry the same part numbers, so I'm curious as to how the 455 brackets were heavier. The only differences are A/C vs non-A/C.