Lenco ST1200 5spd and Hyatt RS Clutch in '69 GTX Project

1969 GTX Lenco ST1200 5spd Project for Street/Strip:

I received my Hyatt Racing services complete clutch assembly for my 1969 GTX, and Hyatt also modified my Lakewood bellhousing by adding a SFI rated Window/Cover for me.

Hyatt also sent me a 10 page manual on setting up the clutch for street or strip.

The Flywheel is the Steel McLeod 143 tooth for the 11" Clutch disc. Hyatt's also machines a "special pattern" on the flywheel and PP faces...it looks beautiful!

I will post pics as I progress on my project, and I am expecting my Lenco to ship at the end of this month.

Mark

Pictures of the Hyatt RS Clutch setup

I like the bell! May I ask what they charged to "fix" it?

Hi Jeremiah,

They charged $150.00 plus shipping, however they may have given me a discount since I had to wait so long. Tim Hyatt's son Chris, finished the Bellhousing for his dad.

I am really sad that Tim passed away, and my clutch was one of the last things he worked on, so the clutch is now very special to me. Tim really helped me out selecting the right parts and the Lenco for my project.

BR, Mark

Nice !

Very nice! Someone else had big problems with their Lenco. I hope your project goes smoother.

SGcuda,

Thanks, and do you know what problems they had with their Lenco?

I ordered mine with the HD Sprags...

BR, Mark

Bolt pattern alignment with the Lakewood shield, I think was the biggest problem. Don't remember exactly, but I think he was having issues with bearing retainer fitment or maybe release bearing setup. I'm pretty sure it became enough of an issue that he was selling the Lenco for something better suited.

Nice looking set up, Is there a reason for a non- spring disc ? Seem like that would really put a slam into the transmission

Hi Rowin4 & sgcuda,

Tim Hyatt told me that the type of disk would be street friendly with the Lenco. The static pressure is set at 1475#, however, I would need to bring that down to 800# for the strip.

I did send the bellhousing, fork and throw-out bearing to Tim to make sure that it would work correctly, and I also purchased the Browell tool to make sure the housing is centered.

I did give all of the bellhousing & clutch dimensions to Lenco, so hopefully everything will work correctly. I do have a great machine shop near my house, just in case of needed mods...

My GTX weighs in at 3550# with no driver, and with the new engine that I am building (slow going because of $$$) the Hemi will be in the 800+ HP area, and Tim Hyatt told me that the Lenco ST1200 was the only transmission that would handle the HP/torque.

The temporary engine that I have now in the car is about 680HP (Dyno'ed 580HP prior to CNC porting of heads and increased Compression ratio...so guessing at 680 as per the engine builder.

Chris Hyatt has the ST1200 in his Street/strip Nova, and he told me that it is a real blast racing and on the street, but he did tell me he has not much road miles on it.

I am keeping my fingers crossed, and hoping for the best!

br, Mark

That clutch is designed to slip. Have had that clutch in my GTX for 15 years now. Is Chris taking over for Tim and keeping HRS going? Any pictures of your GTX?

Hi JericoGTX,

Tim selected a disc that would work both on the street and the strip with high HP...it will slip a small amount for the street, and with reduced static pressure it will slip much more.

I did not get a full answer to that question from Beth or Chris, but then again, a lot has happened for them. They do have other employees from what I could gather.

Have you been driving your clutch on the street?

br, Mark

I like the window on the bellhousing. I thought that NHRA would not accept mods to them. Not a bad price for the upgrade. How do you recert the housing now, since it is no longer a stock Lakewood piece?

x2!

The window is a Lakewood Factory piece for their bellhousings, and yes it is SFI Certified by Hyatt Racing Services.

The window also has the cut-out piece welded on the inside from Lakewood, so that area is 1/2" thick. Added weight, but safe. Also, the window is at the bottom so I can adjust from under my lift.

SGCuda, is the person that you know that had trouble with their ST1200 on Moparts? As I would be interested knowing the exact problems he had. Thanks!

BR, Mark

He was having trouble with the input shaft, he never ran the lenco.

I run a Lenco CS1 behind a Bruno drive. I have had the reverser give a little trouble but that's it. Everything else has been golden like Maverick

hi FastmOp,

Who is he, and what was the problem with the input shaft?

Someone in another thread told me that he never got his input shaft for his ST1200...not sure if this was the problem.

BR, Mark

lockjaw, yes, he's a member. He was so fed up, he listed the Lenco for sale here. That might be a way to find out who it was. Pretty sure it was a ST1200 also.

Man, I sure am forgettable lol. That is my st1200 and I fugured out what is happening. The old lakewood 15330 was drilled for an a-230 similar to a stock bell. The Lenco adapter plare isdrilled for an a-230. They discontinued the 15330 and superseded the part number to the already existing pn 15335 which does not have the smaller a230 pattern. I purchased another 15335 and am sending it anf the input shaft to Matt Moore at Lenco so we can make it work. Hopefulley all of that makes sense.

If this pans out it is game on for the tunnel ram 511, fogger equipped 66 charger project we have. I am using the g force gf5r 5 speed in my other car.

Thanks for the info on the window. Lakewood should add that option standard! Now I have $500 of bellhousing mods and shipping we can look forward to lol.

hi Jeremiah,

I have the "old discontinued" bellhousing...are you saying my 15330 bell won't work?

Did you have the later mfg 15335?

I guess I am a little confused on what bell you actually have.

BTW, Chris at Hyatt RS told me that as long as you have the original bellhousing serial number from Lakewood, they can recertify it. Or, you can send back to Lakewood for them to modify and certify.


br, Mark

"The old lakewood 15330 was drilled for an a-230 similar to a stock bell. The Lenco adapter plare isdrilled for an a-230. They discontinued the 15330 and superseded the part number to the already existing pn 15335 which does not have the smaller a230 pattern. I purchased another 15335"

We now own two Lakewood 15335 bellhousings. Hopefully I can make them work in their respective cars.

Very nice looking B-body! I think you're gonna need more hood pins with your new motor.

i have one of Tim's clutches, i ran it on the street for a summer. long as your left leg is up to snuff they work good!! It will squeak a bit when its hot if your trying to maneuver around tight spaces like a parking lot. mine would still be in there but i ran out of sacrificial hemi 4 speeds...

Hi pro sport, thank you, however a good friend of mine did the original restoration.

68hemigts,

Thank you for the picture, and I am hoping for good results. Tim Hyatt told me that the Lenco St-1200 would be the best to handle any track use. He also told me that the street manners are very good, and that clutch use would be at a minimum.

I ordered mine with the heavy duty sprags for any driver error for the street.

BTW, Very nice '68 Dart you have!

Br, Mark

I'm glad to not be going down this road alone any more. Thank you for sharing your research. After looking at the pictures it appears that you have the 15330 bell so it should be good.

Keep us updated!

I received my Browell Bellhousing alignment tool today, and it is well made!

Too cold here in Cincinnati to work on the car (5 degrees outside & too cold in the garage)!

BR, Mark

Those sure are nice I have a few machinist buddies out there that will make one for me after I get the blueprints done. I want to have the register adapter machined so it will do large and small bell openings,just flip it around for whatever retainer you have.
Sounds like it's going to be an awesome machine

Gus

Here are the pictures of the RobbMC Starter to clear TTI Headers, and a very well made product.

I also used RobbMC Offset dowels, and they are very well made, and worth every penny!

Got everything aligned and ready to mount the Lenco, which should be here around the 8th of February.

Nice setup! Just an observation, will that white paint stay after heated cycles? I wouldn't want you to have to make adjustments under the car and not be able to tell what hole is what...

Nice setup! Just an observation, will that white paint stay after heated cycles? I wouldn't want you to have to make adjustments under the car and not be able to tell what hole is what...

Hi Dave, yes it is high-temp paint. I also have a window in the bottom and can mark them as well.

Bob, car should look familiar, it was Labrat's(Randy B's).

yes, it is Randy's GTX!

I will race it with his motor to get it in the 10's as Randy wanted, then off to putting a Aluminum Block Big inch Hemi!

Then 9.90's

Mark

Mark

Sounds awesome!
A big Hemi/Lenco , Randy will be smiling up above!
Think you're selling yourself short with the 9.90's running 800+hp. keep us posted with your progress, maybe see ya at Norwalk sometime.


Kevin

hi Kevin,

I am doing all of the upgrades that Randy wanted to do, and then some...

I am hoping the lenco will work out for the street, but I trailer my cars most places anyway.

I am planning on attending the Mopar Race in Norwalk this year, and I look forward to seeing you all there.

BR, Mark

Yeah I'm sure Randy would approve I'm really glad someone like you got that car.Randy and I discussed putting a stick in that car after his hip surgery but that's about all the further it went.
Nice car,hope to have my Savoy back together before Norwalk in July.
See you then.
Gus

I got my Lenco and shifters today, and Lenco will ship out my input shaft and bearing retainer on Monday!

I was told to run 10w-30 motor oil in the transmission, and not ATF.

More to follow of my floor pan (small area rusted out) and tunnel mods.

Sure is purty, hope you get it all together and make it to Norwalk this year, I would like to see it in person.

Curious question? It is at 1475# now. How many turns in or out does it take to adjust it down to 800#?
Thanks
Jerry

You would have to check with Chris. Depends on the spring pressures and the thread pitch.

Hi Jerry,

Tim Hyatt told me 3 full turns clock-wise to get 800 lbs...he told me that he uses custom springs in the soft-loc PP.

BR, Mark

That's great ....Randy is definitely smiling down. Just happy to see it in good hands.

I hope you ordered the extra tall shifters for that Lenco
Looking forward to seeing it this summer at a dragstrip near us

Gus

Hi Gus,

I am planning to attend Norwalk this year...I just need a helmet and new seat harnesses.

See you there!

Awesome!!

A few more pictures of the install...sill have to finish trans cross member. just tacked in for now.

Waiting for the input shaft, bearing retainer/tube and yoke from lenco.

will post more as I progress.

Wow that fits better than I thought it would Glad to see more guys not afraid to cut a big hole in the floor to get transmission they want in the car . Have you put the shifters on and made a few passes yet

Gus

Really cool....What does that unit weigh with the clutch and everything?

That is awesome!

Hi Dragula,

It weighs about 130 lbs with shifters, and the bell, clutch and PP weighs about 80 lbs. Just a little more than the 727, converter, lines, cooler/fan and fluid. The 5spd Lenco uses about 4.5 quarts of 10w/30 motor oil.

Mark

Another picture, but my floors have a little rust through that was hidden by some glued/screwed sheet metal...damn. Ordered R/L front floor pans, and will section the bad areas out.

More to come...Mark

Actually that doesn't look too bad, keep it tight and it won't look so out of sorts.

Couple more pictures...Drive shaft, trans mount, and DS loop all installed. A little more welding underneath, and ready to finish the floors that have some rot.

Wow that is one pretty chunk of transmission right there

There sure are some awesome stick Mopars on this site

Gus

Should put a 4 speed hump and boot for every lever! That would be nuts!

I had to modify my torsion bar crossmember and reinforce it to install a 200R4 in my A-Body. It looks like you cut the torsion bar crossmember completely out over the transmission and notched your bolt-on rear motor mount too. I'm curious about your solution for reinforcing those areas to get the strength back into those critical chassis components, especially on a torsion bar car. Please post some pictures of your set-up.

I'm no expert, but it looks like adding a second crossmember towards the rear of the transmission tied to the sub-frame connectors would work a lot better than the long tubes your using for an additional rear motor mount attaching point. The leverage those long bars have to work against those minor attachment points on the crossmember don't look like they would last long with the forces at work against them.

Hi JBC, yes, I have been thinking that as well...great idea, thank you!

I looked at my car today, and you gave me a great idea. Thank you again.

Also, if someone out there knows how to hide the shifter pushrods and the shifter towers that stick out the tunnel, I am open to all ideas.

This is why I love posting on Moparts...always great ideas!

BR, Mark

Mark, I'm sure Randy is looking don and grinning ear to ear! can't wait to see it run!

Randy

I did the frame connector mount deal for my 6 spd swap.

Beautiful rear transmission mount. Are you running torsion bars or a coil-over front suspension? If torsion bar, you may want to reinforce the torsion bar crossmember, or you will begin to see cracks on your floor pan due to the flexing of the cut-out crossmember.

Thanks for the response. I bet that is going to be a beast.

Pictures of my 3" custom 304 SS exhaust system that I built to clear the new transmission.

U do nice work. I likey

Thank you, Rick!

I am a little worried about that 8 3/4 rear with a healthy big block and a Lenco

Gus

Hi Gus,

I will replace the center section with the Aluminum through-bolted unit.

Should be strong enough then.

BR, Mark

Very Nice! I will be looking out for you. I'm building a 69 GTX clone street/strip car. Body, suspension and interior is almost done.

Hi Markz528, very nice GTX and garage!

I live over by the Kenwood Mall here in Cincinnati.

br, Mark

Wish it was my garage. Le Hodge is doing the car body and interior for me. Should be home soon.

You aren't too far away from me..............

Update:

New front AMD floor pans sectioned and welded in, primed, seam sealed, painted with body color and installed dynamat over entire front floor.

The dynamat is quite heavy, however I was able to cancel out the additional weight by installing .063 SS mandrel exhaust system which was about 15# lighter than the steel TTI crush bent H-Pipe, and I saved another 5# off of the mufflers.

I still may install a center console to hide the shift rods, and to cover up the holes in the tunnel for the shift towers and the slot for the reverser rod.

New molded carpet set from Brewers was also installed.

More to follow.

Mark

IDK but I love the linkage in the cab. Just says the rest of you are pussies.

But that's just me.

Hi Madscientist, I am concerned how much heat will come through the tower holes since they are oblong cutouts, and that is where the fill plugs are at to fill the transmission full of oil.

Now looking at my pictures, I may not be able to hide much inside the console...maybe I could get a upholstery shop to make a long cover that will slip over with Velcro???

I am a couple of days away from a re-fire of the car :-))

BR, Mark

I would think a good upholstery shop could make some covers with Velcro. I like the idea. Lif you have to R&R the trans anything you can do to make it quicker is better.

And like I said, I love the look of the shift rods like that.

Hey Mark, your GTX is looking great, love the Lenco!

John

Hi John, thank you!

Or the nodular from Dr.diff I just set up and installed in my Dart..............GREAT WORKMANSHIP...........

Hi Thumper, but the Aluminum one is lighter and cooler looking ;-))

So true man..............

Radiator had a small pinhole leak from installation of the engine without pulling the radiator...repaired but leaks.

I installed a Be Cool 1000HP Crossflow retrofit radiator that is much bigger.

Mark

Lookin good.

Thanks Rick!

Mark