68 Valiant Hellcat Swap

[hemivaliant57]

Onto the fab work;
Utilizing the T56 kit from @Tjfly4pay made the job that much easier when fitting this monster transmission in an A-body.

On the drivers side, the original transmission crossmember placed the transmission to high which created a weird angle for the 6 speed. To correct this I cut the bottom out and lowered the cross brace a quarter of an inch.

Using 18 gauge steel I made a two piece tunnel to fit over the massive hole in the floor.

I had to add a floor extension to the drivers side floor pan where the old 4 speed tunnel was.

With the running gear still in place I tack welded the tunnel in place, to be full welded once everything is removed.

 

[hemivaliant57]

Before I removed the running gear I begin designing a firewall.

The supercharger lays inside the car about 4 inches.

Rather than modifying my current firewall I decided to start from scratch without interfering with the steering column and pedal components. I wanted to create a uniform hole in the firewall so both sides match. In reality the opening in the firewall could be half that size. I also removed the the wiper motor opening and will mount the wiper motor on the inside. I also bought a 10x10 heater box from vintage air to give me more room under the dash.

 

[hemivaliant57]

With the running gear back out I weld the tunnel inside and out. I didn't like the angle my foot was at with the original floor pan so I cut it all out and made a new extension which came down slightly lower.

 

[rumblefish360]

I so gotta stop by and see this thing again!
Pictures do not so this thing justice as when your standing under this machine, you really just gotta love it even more. Beautiful job!
Dang!

 

[A408Cuda]

Im working on the upper cross member for my TKO 600 install and I haven't decided exactly how to approach it yet, you inspired me with your set up, great work!

 

[hemivaliant57]

A Durango came by the shop wanting to swap an SRT8 hood on and I couldn't resist...

With the running gear out I fitted my headers from TTI with my Borgeson steering box. I elongated the mounting holes for the steering box at the recommended .810 and massaging was still needed on the one primary tube. The headers I used are the 64L-R1. 2 inch primaries with the 3.5 inch collectors. They are for the stock suspension setup.

 

[txas2step]

Just swallowed my tongue.

 

[NC Engine Builder]

This sir, is 100% bad *** hot rodding!! I admire your build skills!

 

[ValiantRacing]

That is kick ***

 

[Buford19]

Onto the fab work;
Utilizing the T56 kit from @Tjfly4pay made the job that much easier when fitting this monster transmission in an A-body.
View attachment 1715180995 On the drivers side, the original transmission crossmember placed the transmission to high which created a weird angle for the 6 speed. To correct this I cut the bottom out and lowered the cross brace a quarter of an inch.
View attachment 1715180997 View attachment 1715181000 View attachment 1715181001 View attachment 1715181002Using 18 gauge steel I made a two piece tunnel to fit over the massive hole in the floor.
View attachment 1715181003 View attachment 1715181004I had to add a floor extension to the drivers side floor pan where the old 4 speed tunnel was.
View attachment 1715181005 View attachment 1715181006With the running gear still in place I tack welded the tunnel in place, to be full welded once everything is removed.
View attachment 1715181008

Just a question about the upper tranmission mount,is it still needed if a person is not using the torsion bars? Going with a aftermarket k member, which eliminates the use of torsion bars. In this case,can I just use a lower tranmission cross member?

 

[toplscuda]

The should is coming along nicely. Very well done. Maybe I misread it but if you refused to two mounting bolts that had to be swapped for the pickup tube that would concern me a bit as they are a torque to heidi bolt and it is recommended they be replaced if they are ever disturbed.

 

[hemivaliant57]

Just a question about the upper tranmission mount,is it still needed if a person is not using the torsion bars? Going with a aftermarket k member, which eliminates the use of torsion bars. In this case,can I just use a lower tranmission cross member?

Any cross brace in a car gives it additional support. However, I have seen some builds where the torsion bar brace is capped off and left alone. That being said, on a car with torsion bars the torsion bar brace needs to be strong when the suspension is under load and I would definitely recommend it.

 

[hemivaliant57]

The should is coming along nicely. Very well done. Maybe I misread it but if you refused to two mounting bolts that had to be swapped for the pickup tube that would concern me a bit as they are a torque to heidi bolt and it is recommended they be replaced if they are ever disturbed.

I believe what you are referring to is a Torque to Yield fastener. The main bearing cap bolts are actually Torque to Angle fasteners. Everybody has a different opinion, but I have re-used Torque to Angle fasteners before in the past with no issues.

 

[RealWing]

I believe what you are referring to is a Torque to Yield fastener. The main bearing cap bolts are actually Torque to Angle fasteners. Everybody has a different opinion, but I have re-used Torque to Angle fasteners before in the past with no issues.

yes, they are sometimes called torque to Angle, but they are still torqued beyond their yield point. ie the bolt is permanently stretched. It is no longer as strong and the clamping force will be less if they are reused. From my engineering perspective - they are junk after 1 use. This is a bit of info on TTY head bolts - but same concept as main cap bolts. Why should torque-to-yield head bolts be re-used
My $0.02
Jim

 

[Hellcat Cuda]

Great work and great progress! I'm having to live any progress on my own HC Cuda project through your pics until my home remodel is done, so please continue posting.

Although it can get expensive, I've always replaced TTY bolts to be on the safe side, even though I did not fully understand the concept. Thanks to RealWing for the informative link. Losing a head bolt could blow a head gasket, but losing a main bolt could be catastrophic, I would think.

Hemivaliant57, it appears the intrusion into the firewall is largely the passenger side of the water manifold, is that right? Doesn't look like the driver side intrudes. (close, but no intrusion?)

I've already completed considerable mods to my firewall, so I REALLY don't want to tear back into it if I don't have to. I'm considering a mod to the supercharger. Will post up what I find if it's possible.

 

[Bakaruda]

Great job!

 

[MrJLR]

Wow......


Freaking awesome!




Jeff

 

[hemivaliant57]

Great work and great progress! I'm having to live any progress on my own HC Cuda project through your pics until my home remodel is done, so please continue posting.

Although it can get expensive, I've always replaced TTY bolts to be on the safe side, even though I did not fully understand the concept. Thanks to RealWing for the informative link. Losing a head bolt could blow a head gasket, but losing a main bolt could be catastrophic, I would think.

Hemivaliant57, it appears the intrusion into the firewall is largely the passenger side of the water manifold, is that right? Doesn't look like the driver side intrudes. (close, but no intrusion?)

I've already completed considerable mods to my firewall, so I REALLY don't want to tear back into it if I don't have to. I'm considering a mod to the supercharger. Will post up what I find if it's possible.

You are correct. Most of the intrusion was on the passenger side, however the water manifold was very close to the firewall in the center. Almost too close for my liking. I already was doing extensive fabrication work to the car so it didn't bother me to start from scratch and get the clearance and look I wanted.

 

[Hellcat Cuda]

I wish I had the time right now to set my engine in the car, but no can do at this time. I tend to at first, consider new Mopar engines/parts the "holy grail" and not want to disturb the "factory assembly" of them. Later, that aura diminishes and I start in with the good ol' "hot rodding" as necessary. I talked to a guy who knows superchargers of all types and he made me feel at ease with this IHI. I ordered a new water manifold to modify. I plan to cut the center out; cut and mill the end pieces down to a minimum and tig some 90 degree AN fittings to them for hoses. The hoses will likely be run out each side of the blower and join up to a remote tank. I've got too many details in my mind about this for trying to put it in type, but I think I can work out a nice, clean alternate to the factory, overall low pressure cooling system. I will likely include an ice tank somewhere for when I take it to the drag strip.

I'm excited to see your solution progress. It should look real nice with the firewall all finished off with a relief in it for the manifold. Please keep those pics coming! Any progress?

You are correct. Most of the intrusion was on the passenger side, however the water manifold was very close to the firewall in the center. Almost too close for my liking. I already was doing extensive fabrication work to the car so it didn't bother me to start from scratch and get the clearance and look I wanted.

 

[74Dart318]

Very cool build. Commenting so I can follow along.

Great work.

 

[Hillside hemi]

Sick!!! Sweet build.

 

[hemivaliant57]

A few more updates on the build...
All welds were grounded and the transmission tunnel was all body worked

I used a urethane primer to seal the body work and bare metal. The floor will be wet sanded once I am ready for paint.

 

[hemivaliant57]

The firewall was probably one of the most time consuming because I wanted to make everything look like it belonged without just having a square indentation in my firewall.

 

[hemivaliant57]

By creating a rectangular insert for the firewall it made it much easier to fabricate in and out of the car when needed.

Although it may not look it, but there is plenty of room behind the supercharger for the air charge cooler sensor and fuel rail pressure sensor.

Once I was happy with the placement I tack welded the insert in place and then made a surround with a flanged border to complete the firewall.

Continued the top flange of the firewall straight through for a more cleaner look. Also spot welded the flange to the firewall like the factory would have.

 

[rumblefish360]

Holy snikes!