My outside and inside of my '66 Cutlass 442 finished. This 442 is cherry. I am trying to finish little items before my new engine is ready. I have a new 428ci being produced so I am going to need to have everything right underneath and behind the power-house that Mark Remmel, Winter Haven, FL aka Cutlass EFI is building for me. I have my nine inch Currie with a 3.89 gear ready to go in. When I ordered the Currie I specified disc brake so I only need to convert the front. The Tremec 5-speed that I would like to purchase next comes in 3 gear sets. I would like the 2.87, 1.89, 1.28, 1.00, 0.68 gear set. I need the 0.68 o.d. because when I finish the ride I am riding out in it! I have tire height of 25.8". My engine will have 450hp+ with 500 ft lb+ tq. Are my other gears ratios going to be good to buzz around to the golf course and o.d. good enough to run 75mph down the hwy?
Also, what is the best spring combination? 550# Front 250# Rear? I am changing everything for this engine. Coil-over with new springs, torsion bar, control arms, ball joints & anything else that is not shinny under there!

 

Pretty car! As a cautionary note, I don't know too many people successfully running a 5 speed. They don't get along well with Olds torque. A Txx 6 speed is much stronger. You can calculate approximate rpm using your transmission final gear and rear gear ratios and tire height
https://www.tremec.com/calculadora.php
I've "heard" that 3.89s can be noisy in 9" rears, but have little experience in reality.
Picking springs can be tricky. Luckily, most GM A/G body springs are interchangeable from 1964-88.
​​​​​​I just recently switched from newish Moog 6319s in the back to 7 year old Eibach pro kits; ot dropped 1".
I forget what's up front. The 1/2" taller ball joints made a night and day difference in handling as it decreased the camber change through suspension travel. Moving the caster up to the maximum allowed by the cross shaft bolts and adding negative camber helps as well.
I have IROC springs in the front of my 85 G body with 2" drop spindles, and it works very well. Everyone has different tastes in ride height; don't know what you're looking for.
The spring chart on Moog's site is fun to play with
https://www.moog-suspension-parts.co...oilspringchart
<cue engineer types poo pooing alterations from stock geometry!>

EDIT: just reread about the coilovers- no help there, sorry

 

I should have list the differential is an Eaton Truetrac Posi
Don't know if this creates more noise at 70mph.
I would like to here the radio a bit traveling on the highway.

In order to put a 6-speed in i will need to cut a perfect no rust 56 year old automobile.
I have been told by Temec that the 5-speed TKX will take over 500hp and 600# torque and fit with no body modification.

 

I had a TrueTrac- great unit. I was referring to gear whine. I put a billet locker in (mainly for track use), and that sumbich is LOUD. I get a lot of funny looks from the uninformed.
Cutting the floor is why I still don't have OD. I stuck with 4 gears, an AutoGear M22W. I run 3.70s, and it runs about 65mph at 3000rpm. (28" tire, 275/60-15)
Thinking about spring rates: 550 is a little soft on the front for my taste. The IROC Moogs are 640, and still soft for a v6 G body. If you already have them, it will be a great starting point.

 

I will look into a good set of springs in the 800 area and get back.
Thank you & I really like casting a net out and looking at almost all great information that I get back.

 

Don't go jumping to 800s yet. You might like the 550s being softer for ride quality. I'm a bit of a loose nut behind the wheel

 

“The Tremec 5-speed that I would like to purchase next comes in 3 gear sets. I would like the 2.87, 1.89, 1.28, 1.00, 0.68 gear set”
You must be looking at the TCET17722? That trans is the rebirth of the Legend LGT-700, this unit fit my ‘71 like a glove with no cutting. There are a couple of shifter locations, so take good measurements before ordering. I’ve ran this 5 speed for thousands of miles, love it!

 

Yeah, the new TKX is supposed to be improved in shift quality and strength, including fitting under the car over the TKO. Those are nice ratios, basically a nice spread between gears and a good OD gear. At 75 mph, you will be at 2600 rpm with those height tires. That should be very comfortable with the combo Mark picked. The SEFI with help drivability and mileage as well. We are approaching $8 a US gallon for regular, exactly why I am also going with SEFI.

 

That’s a pretty steep overall first gear ratio and you have short tires.

A friend has that same trans/ratios with 3:55’s and a 455

he rarely uses first gear except at the track. He can burn the tires of it on the street from a stop in 2nd

your overall 1st ratio is more than an old Muncie close ratio with 5:00 gears

 

The TKX should handle your power output easily - it's rated for 600 torque and sounds to be a bit more robust than the TKO. I talked to Jeff at Silver Sport Transmissions (one of many Tremec vendors) to make sure I was making the right choices based on my anticipated 450+ HP/500+ torque engine. Based on his recommendations I went with the same gear selection you did, and a 3.73 rear end gear and 27" tires. I chose SST as a vendor because I like what they offered for full conversions - I'm going from a column shift automatic to the floor shift manual and needed everything. I was really happy with their support and the entire transaction.

Check out 442Dude's build (https://classicoldsmobile.com/forums...to-mod-148439/) - I think he was pushing closer to 600 pounds of torque through his TKX and all was good at last report. He has 4.10 gears, and listed his tire sizes in his thread.

Don't know if this is of any use, but it shows your RPMs at various speeds...

 

Thank you all so much. The chart was what I needed to see. I do not care much weather I am taking off in 1st or 2nd. I was looking on the other end. 2,411 & 2756 rpm at 70 & 80 mph is what I am looking for.
I am going to go to Silver Sport.Transmission for their turn-key full conversion kits. Their name has come up 3-4 times in the last week. I have spied on their website without speaking to anybody. Do you have a name to drop?

 

I do most of my own stunts. The 5 speed will hold up if you don't hammer it on sticky tires.

 

She's a lady and has no need for hammering.
I would never put her out in the street that way.
Thanks for all the info.

Best Regards All

 

When Keisler went down I’m pretty sure Jeff Kauffman and John Czahoroski went over to Silversport, good, knowledgeable guys, John really helped me with my shifter position issues, to make sure I could use my console..

 

I dealt with Jeff Kauffman.