Small block with th400

[HustleRussell]

I’m thinking about installing a 350 smallblock, th400 and 12 bolt rear end in my 68 rs for drag strip duty. Later on the smallblock probably will get changed over to a bigblock. My question is should I use bigblock motor mounts on a smallblock with a th400 crossmember and th400 driveshaft? So when I change over to bigblock nothing has to change, except engine?

[ko-lek-tor]

If you have s big block radiator & shroud , then yes, I would go ahead and and get the bb frame stands

If you do not have a bb radiator with the bb frame stands, then you will either have to leave the shroud off ( it will run hotter and be a constant safety concern with the car running). Or, modify the shroud.

Or, use the sb mounts & radiator and modify the trans mount.

If it is a true drag only car, then, that is what sawzalls and torches were made for. If you don’t run a power booster, I would think that you could run the small block frame mounts shroud, radiator, and modify the trans x member. I see bb and sb shroud setups done all the time on these Ebay clones. A lot of those bb cars run a th350 though. Hope this helps and I hope there is no misinformation. 68 frame mounts are different then a 69.

[bcmiller]

My opinion if you are thinking big block down the road, just simplify things and go that route now. 

[HustleRussell]

Thanks for the advice. The 68 currently has a six cylinder radiator and no shroud. So I’ll purchase both of those for big block. Wanting to start off with 350 engine first because I’ve got one that’s race ready.