Tremec 5 speed conversion in a 1970 Charger

Kern Dog · Jan 20, 2021

I mentioned before the tendency when working on a big project to keep finding more and more things to do....I call it The Snowball Effect.
Succumbing to that often turns a 3 week project into 3 years.
It is tempting to address every little thing you see when the car is apart. It makes sense to fix things that are now right in front of you but at the same time, you have to know that each diversion delays the finish.
Some things you can't ignore, stuff that gets buried makes sense to fix even if it delays the completion.

At first, I figured to leave the exhaust connected to hold the engine in position. Once I removed the right header, I started to think about how the engine has sat out of level for awhile. The passenger side sat lower by a noticeable amount. I figured that with a new transmission going in, I should get the engine sitting right.

Kern Dog · Jan 20, 2021

Another One of the reasons that it made sense to get the engine level is that the hole to be cut in the trans tunnel is determined by the position of the engine.
The instructions state to measure from the trans mounting face on the bellhousing and mark the underside of the center of the tunnel. The rearmost measurement is supposed to be clear of the torsion bar crossmember.
If the engine is out of square or out of level, the measurements are meaningless.
Using the tall jackstands, I loosened the motor mount bolts and jacked the right side up until it sat level side to side. There was about a 1/4" gap between the motor mount and the pad on the K member.

Then I took a look at the right side motor mount....

I didn't like those cracks! The rubber measured 1 1/16". I measured another mount I had in the shed. It is in good shape and has never been installed. It measured 1 1/4".

I figured that this would put the engine back to level side to side. In case it didn't, I made a shim...

Kern Dog · Jan 20, 2021

I was able to get the engine nearly level side to side but fore and aft is a difficult target. All V8s sit out of level, low at the firewall end.
The SST kit came with a new dropped crossmember and trans mount so that height is already established. The trouble is, with the floor intact, I can't fit the trans in place. I can't figure exactly where to cut the floor because I don't know the proper angle that the engine and trans will be once completed. With no trans in place, measuring from the bell with the back of the engine too low results in the hole in the floor being too far rearward.
I suspect that I had the back of the engine too low since many years ago when I changed the trans crossmember. I had a Gear Vendors overdrive and everyone told me that the trans tunnel would need dimpling at the 10:00 and 2:00 positions. Mine cleared with about 1/2" to spare. Now is the time to get it right. The new mount resulted in the right side sitting slightly higher. I expect the mount to compress slightly after driving awhile.

This will probably mean that I'll need to cut the exhaust pipes and angle them a little to sit squarely to the header collectors.
I bought new gaskets today:

Kern Dog · Jan 20, 2021

Going back to this part of the instructions....

Note the measurements on #4:

This is where things started to make sense.
With the engine tilted back at the same angle that it was with the 727 in place (Verified by measuring the clearance above the top bolt on the header collector)

The angle makes it look like there is 3 inches of clearance but it is actually 2 1/4".

So, with the engine at the same angle as before, when I measured for the holes to drill, the rearmost mark was into the torsion bar crossmember. This told me that the engine may be tilted down at the rear too much since the more the engine tilted back, the further it pushed the point from where I started measuring.
I unbolted the header collector then lifted the back of the engine up with the screw jack on the jackstand until I got 15 1/2" to the torsion bar crossmember then made the measurements....

THEN I drilled the holes.

Kern Dog · Jan 20, 2021

The RobbMCPerformance dowels were shipped Priority so they could be here before Friday. I have carpet coming along with the console center decals next week.
I do have things to do until stuff comes in.
The hole in the trans tunnel can be cut. As usual, I'll start small and only enlarge it where needed. I'll build the cover using the metal they provided with the kit and weld it in place. To seal it off, I bought this stuff for the edges:

With no pilot bushing in place, I could test fit the trans and make sure the hole in the tunnel is adequate AND measure for the drive shaft.

Kern Dog · Jan 20, 2021

The instrument cluster is a Dakota Digital unit using all electronic inputs including the speedometer. They supplied an electronic speed sensor to fit in the place of the traditional speedometer gear housing. It is a 3 wire setup.

I was a bit concerned because the speed sensor on the Tremec is a 2 wire design. The orange cap is the cover for the sensor.

I just called the tech line at Dakota Digital. The man said that using the original wiring, I can omit the red wire and just connect the white and black. Polarity isn't important either.

moparedtn · Jan 20, 2021

Just a quick interjection here to once again THANK Greg for all these detailed reports.
This exact sort of thing is what makes FBBO as great as it is! :thumbsup:

Reference material for generations, right here!

Kern Dog · Jan 20, 2021

My experience in construction often involves building structures that employ similar techniques from one project to the next. When I encounter a problem, I look at what may have been done different to change the outcome.
Regarding the car....
The rearward tilt of the engine and transmission has been digging at me. The fact that I had to crank it up from its place it has been for years had me curious. I suspected that it was lower than it should be but how do you determine the right height?
This afternoon, I had an Ah-HA moment!
This crossmember was modified sometime in 2012. The "block" shaped mount was broken so I modified it to accept the spool type mount. Remember what I wrote about the Gear Vendors unit fitting without any clearancing work? NOW I know why.

This is the stock crossmember I got with my other car, Jigsaw.

Take notice of the height of the top of the mount.

Yeah....The mount sits above the mounting holes by a fraction.
NOW here is the crossmember that I've had in the car since 2012.

Yeah...The spool mount sits 1 3/8" too low! I did have a 1/4" shim in there...

Still, for 9 years I have been driving around with the driveline angle a mile off. The header collectors hung lower than they should be too.
This means that I will certainly have to cut and tilt the exhaust pipe collectors to get them to lay flat and seal.
Snowball Effect or not, stuff like this HAS to be corrected when it is found.

5.7 hemi · Jan 20, 2021

If the reducers aren’t welded, meaning slip fit to the rest of the exhaust, no need to cut the headers when you can rotate the reducer, or whatever it’s called.

CoronetDarter · Jan 20, 2021

Kern Dog said:
Yeah...The spool mount sits 1 3/8" too low! I did have a 1/4" shim in there...

Wow, that's quite a difference. That could explain some of the vibration issues you wrote about in #7. I wonder if the stress also caused the flex plate crack. Good that you found the reason.

Kern Dog · Jan 20, 2021

I pulled the carpet, then set about to remove the shifter pedestal and vertical shift rod.

Before I could do much of anything, I had to remove some of this sound deadener.

Kern Dog · Jan 20, 2021

I marked about where I thought the proposed tunnel cutting would be, then went a little further out. I cut a perimeter with a utility knife, then used a screwdriver to lift an edge to get started.

It peeled up easier than I expected.

Kern Dog · Jan 21, 2021

I measured and recorded the locations of the shifter bracket so when I convert Jigsaw to a floor shift, I'll have an easier time.

The welds were cut with a Sawzall since the 4 1/2" grinder disc couldn't reach the welds.

With the brackets out of the way, I was able to see the holes that I drilled in the tunnel from underneath.

Kern Dog · Jan 21, 2021

The paper template supplied by SST was cut down and laid over the tunnel. I used two 16 penny nails to center the template.

The plan was to cut about 1/4" inside of the outline. It is easier to cut MORE later than to add it back.

I could have made the cut with the grinder but to minimize sparks, I used THIS:

Kern Dog · Jan 21, 2021

Almost through....

Like the guy said at the Strip club.... LOOK at the size of that HOLE !

Now with the light coming from underneath for dramatic effect...

Kern Dog · Jan 21, 2021

The Tremec was situated on the trans jack so that it was not going to fall off.

Kern Dog · Jan 21, 2021

I spritzed a little WD40 on the front bearing collar to help it slip in a little better. The goal here was to get the transmission up in the car with the crossmember in place. This will accomplish two things: It will show if the transmission tunnel hole is adequate AND it allows me to measure for the drive shaft.

This jack has a nice feature....a "tilt" table.

I had a little trouble getting the trans up and in place. Nothing monumental ....The brackets on the jack interfered a little.

The bearing collar is in, now I just need to push forward.

You can see that I have yet to put in the pilot bearing.

5.7 hemi · Jan 21, 2021

Did ya use a nail gun? LOL!!!

Kern Dog · Jan 21, 2021

The transmission seated fine. I bolted it to the bell, then went to lift the tail end enough to get the crossmember in place. The car was on the highest point on the lift and the trans jack topped out without being high enough to get the crossmember in place. I ended up lifting with one arm and jamming a screwdriver in with the other free hand.
Clearance is tight but it fits.

Driver's side

Passenger side makes contact. These floors are original and the car has not been in a front end collision.

I may have to cut or reshape that area.

1 Wild R/T · Jan 21, 2021

Your a carpenter, you should know how to swing a hammer... Honestly often a well applied pry bar will move the sheetmetal pretty easily...

Tremec 5 speed conversion in a 1970 Charger

Life is full of turns. Build your car to handle.

Life is full of turns. Build your car to handle.

Life is full of turns. Build your car to handle.

Life is full of turns. Build your car to handle.

Life is full of turns. Build your car to handle.

Life is full of turns. Build your car to handle.

I got your Staff Member riiiight heeeere...

Life is full of turns. Build your car to handle.

FBBO Gold Member

FBBO Gold Member

Life is full of turns. Build your car to handle.

Life is full of turns. Build your car to handle.

Life is full of turns. Build your car to handle.

Life is full of turns. Build your car to handle.

Life is full of turns. Build your car to handle.

Life is full of turns. Build your car to handle.

Life is full of turns. Build your car to handle.

FBBO Gold Member

Life is full of turns. Build your car to handle.

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