Switched to 3.73 gears and not loving it

Discussion in 'High Performance Modifications' started by sinnyz_me, Jul 7, 2018.

  1. Plant Engineer

    Plant Engineer Veteran Member

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    My next gear change will be from 4.10's to 3.54's and that 3.06 Richmond 1st gear will be perfect. I MIGHT even get 11 MPG out of the car instead of the 10 MPG it gets now. Yay.
     
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  2. Francesco

    Francesco Veteran Member

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    So if I have a 3.73 and 225-60-15 on all four wheels? What would be the ideal rear tire size if I want the maximum in performance out of a 3.73 gear?
     
  3. Plant Engineer

    Plant Engineer Veteran Member

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    Maximum performance RPM range is going to be based on cam, intake, heads, transmission type, desired use etc.

    What are you looking to do?
     
  4. G72Zed

    G72Zed Veteran Member

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    In addition to Plant Engineer's post above, the ideal size is a tire that fits properly, both the rim and body without rubbing.

    And again, depends on what you looking for, traction for drag, lateral grip for handling, or old school radials for mileage and looks, 3 different style of tires (and rims).
     
  5. Francesco

    Francesco Veteran Member

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    I want a nice daily driver that maximises performance with what I modified on the car. I believe the engine is all stock except for the mufflers that are not original equipped with crushes, performer intake, street avenger carb 770 cfm, 350tH tranz with shift kit and an original rear axle with 5 leaf spring suspension. I don't want to modify the car for racing or drag with 550 hp that will bend a stop sign when I blast my way down the road. I want to have fun on the street and push it from time to time or...Most of the time lol. Right now in wondering what kind of rear tires I should have to make it look bad and get some good stable speed. What do you guys recommend? I recently had a single plane intake and changed it for a dual plane and wow...What a difference. Instant response as soon as I push the pedal! I just cant get enough! Stock I have 170 HP. With my modifications, how much more do I have? Any ideas?
     
  6. Plant Engineer

    Plant Engineer Veteran Member

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    You might be in the 210 HP range. Until you get into a cam change and some head work, a little more compression etc you arent going to be pushing much more.

    Put whatever the biggest tire you can stuff in there. That my motto :).
     
  7. Francesco

    Francesco Veteran Member

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    Yes, that sounds right to me. I told a few owners who have big modz at my local gathering that it was between 200 and 300 to be more broad. My tire expert suggested minimum 245-60 if I wanna make it look hotrod and max 255-60 to be on the safe driving side. 295 felt good in a straight line but when you corner, it feels like beach balls lol. Anyways, thanks for the input.
     
  8. DesmoEd

    DesmoEd Veteran Member

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    I put a brand new Hurst Competition plus shifter on the M-20 when I did my 4 speed swap a few years back and had a pro set it up.

    [​IMG]


    Its good but its not 2 finger butter smooth like the TKO, nor did I expect it to be.

    Nothing wrong with a good Muncie/Hurst combo, but by sheer design, I don't see how any external rod type shifter can best a good internal rail system.
     
  9. DesmoEd

    DesmoEd Veteran Member

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    Thanks for the complements, both cars were a long time in coming.

    It very well could be that I overlooked the different 1st options as I'm going from memory but in reading up the other day I remembered that the Richmond was developed from the old Doug Nash 5 speed and that how the Nash in using a 1-1 final and really short 1st allowed you to run a really tall rear axle ratio.

    I didn't know about the Richmond having shift issues but remember reading about having to upgrade the TKO if you plan to push it beyond 6500rpm. That limitation was not an issue for me as both cars are street only and being retro hyd roller they are done by 6000rpm.

    I was thinking the same thing about having to cruise in the 2800 rpm range and figured with the light flywheel the car would not like steady throttle in high gear/low rpm. I've run light alum flywheels on Ducati motorcycles and while the on/off throttle transitions are outright fabulous they will absolutely not tolerate being lugged in high gear. The '69 really suprised me in that respect as it runs clean down in the low 2000 rpm range without a hint of chatter or lugging, I think its due to the carb being absolutely spot on. Its got a Chuck Nuytten built HP Holley and its absolutely flawless everywhere, its the only purpose built carb I have ever run and it was well worth the cash in retrospect.

    Your combo sounds interesting being a small cube big cam setup with a light flywheel. Please share more info, I have always been a fan of having a destroked high revving small block. For my next vette motor I'd love to build something like a 550 hp solid roller 377 that comes on hard at 3500 and spins past 7000
     
  10. Plant Engineer

    Plant Engineer Veteran Member

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    Richmonds and G force transmissions use Long shifters. They are a completely different design than the old Hurst shifters had. All rod ends and rails . Ive even had a set on a M22 and it made the world of difference .
     

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