Author Topic: Small block with th400  (Read 96 times)

1969Z27

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Small block with th400
« on: December 10, 2017, 01:50:51 AM »
Iím 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?
Russ 
68 RS L22/M20
69 SS L48/MC1

ko-lek-tor

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Re: Small block with th400
« Reply #1 on: December 10, 2017, 03:38:38 AM »
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 donít 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.
James to strangers, Bentley to friends
1969 SS/RS 396 coupe Hugger Orange X22 712 bought in 79
1969 SS 350 coupe LeMans Blue 713 bought in 79
1969 307 4spd. coupe Daytona Yellow 711 bought in 85

bcmiller

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Re: Small block with th400
« Reply #2 on: December 10, 2017, 07:03:29 AM »
My opinion if you are thinking big block down the road, just simplify things and go that route now. 
Bryon / 1968 Camaro SS 396 - now 468 ci, M21, 12 bolt
Looking for 68 Camaro with body number NOR 181016

1969Z27

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Re: Small block with th400
« Reply #3 on: December 10, 2017, 06:52:43 PM »
Thanks for the advice. The 68 currently has a six cylinder radiator and no shroud. So Iíll purchase both of those for big block. Wanting to start off with 350 engine first because Iíve got one thatís race ready.
Russ 
68 RS L22/M20
69 SS L48/MC1