The Stovebolt Site Forums The Shop Area The HiPo Shop 61 C10 engine & tranny swap

Its been awhile since I've checked in. Had some issues and hadn't worked on the truck for awhile. The truck is a 1961 Chevrolet C10 Apache Suburban. Changing from a 235 straight 6 with manual 3 speed to SBC with 200-4R tranny. How do I determine where motor mounts go? do I mount tranny to engine and drop it in and see where it fits? Also, has anyone made a tranny crossmember for this setup? (would be the same for TH350 Tranny). If anyone can point me in the right direction, I'd really appreciate it. Thanks

I have not done *this particular* engine swap, but I have done several others.

The short answer is that you can put the mounts wherever you want them. Since you are changing the engine and the trans, there are no hard datums for it.

If you can buy an off the shelf conversion mount kit for the engine, that will drive the location of the engine mounts (and should have instructions for where to put them). Once the engine mounts are located, the transmission mount location becomes a matter of measuring where the transmsission ends up when the engine is mounted.

If you are not buying an off the shelf kit, the answer becomes a bit more complicated. You still *can* put it wherever you want, but some locations will be easuer than others.

You want to be forward of the firewall, far enough back for your fan to clear the radiation, far enough to the passenger side to avoid the steering (or plan on rerouting the steering like some people do), high enough to clear the crossmember (or plan to move the crossmember), and low enough for the transmission to clear the tunnel in the cab (or plan to modify the tunnel).

My personal preference is to remove the hood, lower the engine and transmission down through the front and just hang it there for a bit while I inspect the clearance and look at how the trans hangs. From that, I can get a decent idea of where I want it to go. I can also see if I need to make changes on the vehicle side to have clearance for the exhaust and whatnot.

With a few hand measurements from the frame and firewall, I can make a rough mount to attach to the engine, set it back in place, tack-weld it on the frame side, unbolt/remove the engine, finish weld/reinforce the mount, put the whole assembly back in and bolt it up.

Once the engine is mounted, then I will fab up a trans mount wherever makes sense from how the trans hangs.

Note that the transmission is attached when I am fiddling on the engine side and I do use it to help position the engine to avoid mounting the engine in a way that precludes the trans being about to attach.

Other people almost certainly have other processes, but that is what has been working for me.

200-R4 wouldn't be my 1st choice.

The 200-4R has the advantage of being the same length as a TH350, but still getting an OD gear. It is not as popular as the 700-R4, but it used to be pretty common in car (Corvette/Camaro) swaps. Assuming a mild 350 build, it should work fine.

But yeah, if OP is planning to do a Hipo 350 build then something a bit more stout would probably be prudent.

@preSUV: Another thought for you: have you considered just getting a set of factory V8 mounts? They were available as an option in 61 and it might be cheaper/easier to get a set of them. That would give you a good starting point for clearances all the way around and be a whole lot easier than dealing with an aftermarket solution.

EDIT: Lets try that again. I told LMC 61, but it gave me 63. Here is the correct link for both I6 and V8 mounts: https://www.lmctruck.com/1960-66-ch...e-1960-66-engine-and-transmission-mounts

This link has some good info on the stock design motor mounts:

http://www.persh.org/pickup/perches.htm

The link is down at the moment, but it was up a few days ago. Maybe it will come back online.

Here is a web archive of the page: Wayback Machine

I think the most interesting thing from the page is that the auto and manual transmissions had different motor mounts. You probably need the automatic style mounts (assuming you are trying to stay stock-ish) which are pretty uncommon.

Factory V8 used the same front mount (cushion) as cylinder. Horseshoe bracket bolts to front of engine block, 2 holes on lower frt of engine block. Period correct V8 bell housing uses same mounts to cross member.
Others will chime in on other mounting methods but for correct look & hyd clutch that's the way I would go.

I have written this up several times in the past on here. As others have also.
1. The SBC should have side mounts.
2. Use a universal tubular cross member. They fit "original" side motor mounts.
3. You can use the same style cross member for the trans if you don't have anything.
4. Mock it all up to determine which cross member shape works. Purchase where returns are free, then mock up again to get all the clearances figured out.
5. The usual issues are firewall clearance/dizzy clearance, exhaust, steering, linkages, drive shaft length/angle, Rad and fan.....
6. Set carb mounting surface level.
7. Sit and stare and think and measure.

Mock up motor and trans with cherry picker slinging, jack stands, blocking, chains....whatever, to determine location of cross members and all other issues. This will not be a difficult swap. You didn't say which SBC or it's year.... and didn't say how you want to shift the 200r4.


Example only

PreSUV: Can you give us some more information on what your goal is?

Are you trying to do a minimum cost or minimum effort swap to get a V8?

Are you wanting to use original style parts so it is the way it would have come from the factory (not including the modified transmission)?

There are a number of different options for how to mount it depending om what your goal is. If you can give us some feedback on the info we have already provided, we can offer better advice.

Thank you for your advice. Its great to hear from others' knowledge and experience.

Some things have changed a bit. The 200-4R trans is not available at the moment. But going ahead using a TH350 in its place. Will swap back to the 200-4R later.
The engine is a sbc 350 from a 1976 corvette.
I have V8 motor mounts from a 66 suburban. Going to use 1" blocks on top of frame.
Engine & trans bolted together and hanging roughly in place.
Frames and crossmember do not have holes or indents to indicate stock locations for engine mounts.
Put driveshaft in trans for fitment.
Engine sits at quite an angle.
With rear of trans/driveshaft as close to torsion bar suspension crossmember as I dare to place it, the trans mount cross member would be very close to torsion bar suspension crossmember, almost touching each other. Also, the trans crossmember would have to drop quite a bit to mate to trans mount location.
There are no holes on frame to indicate stock trans crossmember location.
The trans X-member is my main concern. any ideas on this? Any aftermarket ones?
Going with a column shifter.
Want to make a nice reliable easy driving cruiser.
Doesn't matter, original or aftermarket parts.
Truck came from USA military base near Huntsville Alabama. Only had 30,000 miles on it. Very solid truck.
It was my daily driver from 2008 to 2012.

Any help getting the drive line in would be great, Thanks.