The Stovebolt Site Forums The Parking Lot '60-'66 Trucks V8 engine/ 700r trans swap in 1965 chevy

I'm installing a V8/ 700r transmission in my 1965 chevy truck, I switched out the front end for one out of a 1973 chevy truck. I started by using the motor mount perches from the 1973 truck, I had to add a spacer under the top of the mount because it was about an inch taller than the frame. I ordered an aftermarket transmission brace. After installing I noticed the engine is not level so I lifted the trans up til the engine was level, It ended up being 1 1/2 inches up off the frame. Now the cab almost touches the transmission. I put the perches from the 1965 back on but they actually look higher than others. Have not put everything back together yet. Just checking to see if anyone can give me some advice. This small block is over 500hp, will the perches from the 1965 work with that, if height is better?

Of course, My answers are without seeing any pics.
1. The mounts don't care about HP. They care about weight and some torque. Those values are split/divided between 3 mounts. SBC No sweat.
2. Use the mounts that fit the best.
3. You talk about height and you talk about level. These are two different issues. The motor can be an any height and then be level or not. The Chevy motor has a "designed in" approx. 4 degree down angle at the trans connection when the intake manifold/carb is level. This is to provide a path angle toward differential and provide a good pinion angle. So take a step back and think about what you are trying to accomplish regarding two things. Vertical height of installed motor while manifold/carb-mount is level. (Be sure frame/truck is level). Sling the motor in there on a picker and jacks, with trans attached, and mock up all the parameters as follows.

1. Radiator clearance and proper distance for cooling. Decide shroud or no shroud.
2. Firewall clearance with distributor.
3. Exhaust manifold clearances to steering box and frame rails. Approximate tail pipe direction.
4. Mount trans to a cross member and check attachment to frame.
5. Trans clearance to floor, etc. Shifter stick location/linkage clearance.
6. Motor nested and looks good.
7. Carb level.
8. Pinion angle using a stick back to diff.
9. Balancer and fan blade clearance to frame.
10. Almost touching is not touching. 1/2" clear for most things is OK. Closer depends on relative movement of the two parts.

Examine all that and design best motor mount technique, using whatever is best to place motor there. That is the last and easiest part of the exercize. Weld, bolt, bend, spacer, modify, make work, the motor and tranny mount parts you have or buy some that work better. I.E. universal tubular cross member. Many other kinds of mounts.

Key: MOCK UP, sit down and think. Tweak until all is good. I don't see why you are having trouble with a SBC in a huge engine bay truck that was built for a SBC. Forget thinking about horse power and think about 1 thru 9 and any other parameters that other members may mention. Unless you have a blower on that motor or you have spent north of $6000, you are exaggerating the HP anyway.

Thanks for input. I will post some pictures as I go along with project. No blower but will end up with a lot of money in this engine build.

The mount perches will probably outlast several transmissions, unless you spend a truckload of money beefing it up. TCI (Torque Converters Inc.) has a catalog full of strong but expensive parts to help a TH 700 survive high HP engines.
Jerry

Here is some pictures of what I am working on now. I put the old perches on and put engine and transmission back in. This moved engine back a good bit because now my driveshaft is to long. I leveled the engine by lifting the trans up around an inch. I am hoping I can set cab back on tomorrow, to check clearance of trans bellhousing and cab.

The aftermarket transmission cross member mount is upside down.

I think the tranny mount is just sitting there.. overall that looks like a nice setup.

Actually I flipped the trans mount but the round tubing hits the frame, that's why its upside down. The company that it came from said that would be fine, it does not compromise anything. I installed the cab today with the original perches, engine was too far back. valve covers are hitting firewall. Put perches from1973 truck back on and set cab on, the lip in trans tunnel is touching the trans. Not sure what to do here. Also checked to angle on driveshaft and it was 7 degrees. What is the correct degree? Thanks Rusty Rod

I did the 350/700R4 Swap in my ‘62 last winter. I had to trim the tunnel at the firewall to allow for clearance of the 700R4. Then purchased a aftermarket fiberglass tunnel hump toeboard which extends farther up the firewall to cover the trimmed area.🛠

I bought a '65 C20 with a 283 V8 and a power-glide new. I had trouble with the engine while it was still under warrantee, by the time the engine had 49 k on it the heads were shot. I was considering re-powering the truck with a 327, while looking at the new '68 chevy truck line I noted that a 396, 400 turbo option was available. I went to the local Chevy dealer to check out the C20 with a 396 engine.
A very close look at the '68 chassis revealed that it was very similar to my '65, a plan was set in motion to re-power my '65 with a 396.
I was able to pick up a complete '68 325 HP 396 with 2,300 miles on it from a wrecked Impala. A low mileage 400 turbo trans was secured, I then went to the local Chevy dealer and ordered the 396 frame and motor mounts along with the trans mount.
The engine did not want to sit correctly in the chassis with the factory 396 mount pads, a torque restraining feature built into the mount made the rubber/metal mount to thick. I ended up using earlier mounts for a 327 V8 with 5/16" cable restraints. to over come the torque of the engine. I got the idea from GM, they started to offer a retro for the truck motor mounts due to breakage of the rubber portion of the mount.
Stating in '66 GM offered the 400 trans in their trucks as an option. I ordered the 400 trans shift detent/switch and column selector.
I had to move the trans mount back to allow for the longer 400 trans, and I had to have the drive shaft shortened.
I had a four row radiator made for the truck. The original shroud would not fit so I went to the local wrecking yard to secure a shroud that would fit. I harvested a metal shroud out of a Pontiac, I modified the shroud to fit my truck. My truck had after-market AC so I had to secure a compressor mount that would fit the 396 and work with my system.
I was going to use a stock GM truck exhaust system, however GM could not come up with all of the pieces so I had to have a system built for the truck using the stock manifolds.
I used the truck for eighteen years, over 80 k with no problems, the man I sold the truck to still has it, I just saw him driving it last week. I have tried to buy the truck back many times, the owner won't sell it. Wm.