I haven't posted for a while but i have a 91 b2600i and a 88 2600 i'm making one out of. ALl the suspension is done and am trying to mate the 88 2600 engine with the 91 trans. I'm in the middle of swapping out bellhousing and i relized on the back sides their different. I looks like the 91 bell has an oil valley in it that the 88's bell does not. I was wondering if anyone else has put an 88 bell on a 91 trans or would have any knowledge to help. ANYthing at all would be apprecieated thanks