Transmission tunnel clearance

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Odies dad

Well-known member
Joined
Sep 6, 2016
Messages
116
Stuffing a 291 desoto hemi and a 700r4 transmission in a model a pickup. Body is channeled 4 inches.
Is there any consensus on how much clearance I should have when I cut the firewall for transmission clearance?
Running short on real estate around the steering wheel and pedals, but I don't want to have the bell housing rattling against the firewall and tunnel when I hit the throttle.
 
We're facing the same situation, but different. No chop or channel but foot space is limited in a small 30's era vehicle.

We're also working with a 700R4. We've decided on 1" clearance for the tunnel and we feel it's enough, though it may "warm" the sheetmetal more than comfortably!

.
 
We're also working with a 700R4. We've decided on 1" clearance for the tunnel and we feel it's enough, though it may "warm" the sheetmetal more than comfortably!
.

This is the clearance I use. The only place you could run into an issue is the cooling lines. I've found if you replace the straight fittings with 45 degree, before installing the tranny, it is easier to get them hooked up.
 
I suggest a flexible dip stick tube or possibly a shorty if you don't mind crawling under to check fluid level. I originally had very little clearance,,,less than an inch. It was so close, accessing bolts was a problem. On my first motor move, I increased the clearance as much as I could in critical areas. I screwed up 2 hard dipstick tubes trying to reshape and went with flexible in the end. I went rubber with the coolant lines.
 
Thanks
I hadn't even considered the dipstick.
It was a little tight between the block and radiator but I was able to scoot the radiator forward and I can move the block back a little so I should be ok. The new motor mounts raised the block up a couple inches so I can get by without a water pump riser.
I got the steering hooked up and was very pleased with the ability to spin the wheel with one finger. I can't forsee any conflicts with my steering shaft placement. Most likely, something will pop up.
 

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