Swapping '72 440 drivetrain into my '73: What do I need?

[rt-man]

3 years ago, I bought my '73 SSP (318/904/8.25) after I totaled my '72 GTX clone (440/727/8.75). I pulled the 318 and put in a warmed up 360, mating it to the 904 and 8.25 (except I put in a non-stock converter, 3.55 gears and Sure Grip into the 8.25 rear end). Well, the guy I sold the '72 GTX clone to is talking about selling me back the entire drivetrain and exhaust. We had both cars up on two lifts side-by-side and can see we can't use the BB K-frame from the '72 in the '73. However, the wheelbase and other dimensions look the same. What do we need for this swap?

- know we need Schumacher mounts to put the 440 in the right spot.
- did '73s have different K-members for SB and BB V-8s?
- any other changes in '73s, SB vs BB? Inner fenders? PS pump?

Any help here would be greatly appreciated.

 

[#41]

Yes, the 73 K member small to big block are different.

You will also need a big block center sump oil pan to clear the small block K. Regular oil pans from the 72 (or 73) big block cars will not work with the small block K. The Miloden 7qt race pan works. Need to shorten the driveshaft and use the 727 yoke, lengthen distributor wires, and at least a 26 inch radiator.

The front inner fenders on a big block car have larger access plates, but you don't need to change any of that for practical purposes.

 

[rt-man]

Yes, the 73 K member small to big block are different.

You will also need a big block center sump oil pan to clear the small block K. Regular oil pans from the 72 (or 73) big block cars will not work with the small block K. The Miloden 7qt race pan works. Need to shorten the driveshaft and use the 727 yoke, lengthen distributor wires, and at least a 26 inch radiator.

The front inner fenders on a big block car have larger access plates, but you don't need to change any of that for practical purposes.

The '73 already has a 26" radiator and that's staying with the car. The distributor wires will come over with the 440. The entire drivetrain (tranny, driveshaft) will come over from the '72.

 

[1968rt]

looks like its only the driver side is different. Maybe you can move it

https://www.forbbodiesonly.com/mopa...ication-of-sb-vs-bb-k-member-for-73-74.79241/

 

[rt-man]

View attachment 1146926
looks like its only the driver side is different. Maybe you can move it

https://www.forbbodiesonly.com/mopa...ication-of-sb-vs-bb-k-member-for-73-74.79241/

Thanks. So it looks like (at a minimum) I need either Schumacher conversion engine mounts or a '73-74 B body BB k-frame. I have a text into Mike at the former Schumacher to see when will those mounts be back in inventory. Anyone have a BB k-frame to sell?

 

[Nacho-RT74]

The belts setup also changes specially being AC, mainly because the water pump housing lower outlet changed of side, from driver side to passenger side. This was made because more miscellaneous parts for smogger era were added since 73. An air pump to the carb on C bodies which made to relocate the steering pump deeper down into the engine bay when this was equipped.

You can actually keep the older 72 belts and pulleys setup HOWEVER, if your actual radiator got the lower outlet on passenger side, will need to change the water pump housing for the 73 and lates also on passenger side. If your radiator gets the bottom outlet on driver side, you can keep the 72 water pump housing.

 

[Master Gunner]

The K frame for 75-78 big block B bodies will also fit, there were a lot of Cordobas and Chargers with 400s in them. You may want to clearance the passengers inner fender, it can be a very tight fit with headers. Also be aware that there are 2 water pump housings, drivers side lower hose up to 72, and passenger side lower hose 73 and up.

Mark

 

[1968rt]

Why cant you cut off the drivers side and push it back?

 

[#41]

Why cant you cut off the drivers side and push it back?

Of course you can always build anything you want if you have the tools and skills. The Schumacher mounts only require some cutting/grinding of the existing mount. The templates are included with the mounts, so there is no measuring and figuring things out. The Schumacher set up makes the process very easy.

 

[rt-man]

Thanks everybody! Great input. I may not have been clear: all accessories from the BB (including the 26" rad for it) will come over with the 440, including the 727, driveshaft, rear end, exhaust; that's the only reason why both of us are even considering it. The 440 has HP manifolds, not headers. The 360 does have the original AC, will need to get the BB brackets for it. The main issue is either the Schumacher conversion mounts (and modifying as #41 cited) OR get a '73 and up (as Master Gunner said) BB k-frame. Wheelbase seem to be the same between the 2 cars, as well as most dimensions we took (firewall to the radiator support, etc).

I don't think I'm forgetting anything...as someone on another thread posted, with enough money and patience, anything can be fabbed or modified. Unfortunately, the guy with the BB setup is not patient and will not want to tie up the two bays he has for this project for any length of time.

 

[Master Gunner]

If you go the K frame route, do yourself a favor and replace the isolator pads with at least polyurethane ones (good), or the aluminum ones (best) from Firm Feel. Really helps tighten up the front end.
Even with the HP manifolds, changing spark plug on the passenger side will be fun. If you look at a factory BB car you will see the inner fender has a rubber piece that covers an access, this gives more room, and another (read easier) way to get to the spark plugs.

Mark

 

[Nacho-RT74]

Small/big block AC hoses changes.

The AC belts setup is COMPLETELY diff between small and big block, not just the compressor brackets. Since you are keeping the 72 engine as is, will need to change some pulleys, brackets and add the water pump belt iddler. Fortunatelly everything but the compressor brackets and pulleys are available new.