Anyone driving a 308 7x with a chevy 700r4 behind it ?

Hi , I’m about ready to install my 308  7x copy with a Clifford 4 bbl intake ( no carb yet ) no distributor yet, old style Clifford headers and  a Chevy 700r4 . I’m curious to know if it’s a good set up ? Mileage while in O.D. Etc any thoughts ideas etc, thanks.

Comments

  • Ol racer
    Ol racer Senior Contributor
    edited August 2019
    Great choice. I have a 7X copy with 4bbl & long tube headers in a '37 with a Turbo 350 since a T400 is too large to squeeze between X frame. Have another with a 200R4 since same size as T350. Be sure to install a 'Shift Cable Kit' with either GM OD Trans. Never ck'd mileage though....
  • What. Arb are you using ? Thanks,Dave
  • Carburetor
  • I am  considering doing the same.  How did you adapt trans to motor, as well as what flex plate and how did you attach it.  Is there a Hudson flex plate which will just bolt up to the crank and use Hudson starter?

  • squirrel
    squirrel Member
    edited August 2019
    Bentsens and Wilcap make adapter kits, $935 and $730 respectively. First uses a GM flexplate and includes a starter, second uses a custom flexplate.
  • Glowplug
    Glowplug Expert Adviser
    I have tried to add contact and technical information about these conversions to my website- these adapter company links are on the vendor page.  

    https://hudsonrestoration1948-54.com/
  • I got mine from Randy Mass if I remember correctly . It’s been years. Real simple as you can see. Some of the other adaptors are not. 
  • I do though have a problem. The 700r4 requires 12 volts. My car is still 6 . I think I will pull out the complete harness for my 1952 Hornet convertible project and retire the Brougham for 12 volts. My only concern is the gas gauge water temp cluster. How do I convert those two ? 
  • I discovered that the voltage regulator that is already connected to the temp and gas gauges (on my 51 Hornet) works just fine when given 12v instead of 6v. So, you don't do anything, they just work.

  • Ol racer
    Ol racer Senior Contributor
    edited August 2019
    supersix said:
    What. Arb are you using ? Thanks,Dave

    I use a 600 CFM Holley. I purchased Trans Adapter's from both Randy Maas & Danny Spring a long time ago then locally 'Indexed' a Hudson Flywheel to accept a GM Torque Converter. The center hole had to be enlarged for the Converter Hub too, Today they may have a Flex plate available. The Hudson Hydromatic Starter works fine.

    /

     Note:                                                                                                                                        GM 200R & 700R4 Overdrive requires a 'Throttle Pressure Cable' to control shift points to prevent burning up the Trans. Economical Universal Cable Kits are readily available online...

  • I'm using an Edelbrock 4 barrel on my '40 with the 700R. With 3.56 gears and a 28"tall tire I get 23MPG at 65MPH., but the car wants to go faster than that
  • I have used a 4.11, a 3.56, a 2.73, and a 3.73 in my car. The 700r has a very low first gear ratio, like the dual range hydramatic, so even with the 2.73, it accelerates nicely off the line, I found with this ratio, it wanted to run at about 80-85 on the freeway. That is too fast for my normal driving area, so I'm using the 3.73 now, and for my normal local driving I'm very happy with it. If I'm going to take a cross country trip, I would probably swap in the 2.73's. I'm running a 9" Ford, so it's easy to do. The Hornet engine has plenty of torque to turn the high gears without issue. I'm running a cam with more lift and duration than any 7X cam (402/280).
  • Sounds like you need to get some 3.25 gears for that rear end.

  • squirrel said:
    Sounds like you need to get some 3.25 gears for that rear end.

    I've got a 3.10 I haven't tried yet....
  • 54coupe said:
    I'm using an Edelbrock 4 barrel on my '40 with the 700R. With 3.56 gears and a 28"tall tire I get 23MPG at 65MPH., but the car wants to go faster than that
    My carb is 500CFM.
  • My engine is the 254 eight cylinder.  Wilcap says their kit is for 6 only, but don't say why.  I am under the impression that the 6 and 8 are swappable in a Commodore, so why wont the kit work on an 8 cylinder?
  • 50C8DAN
    50C8DAN Senior Contributor
    Call Randy Maas and ask him, he would know if it fits or not.
  • What year Eight? One locating dowel sleeve is in a different location on pre 48 Eights. 
  • My engine is the 254 eight cylinder.  Wilcap says their kit is for 6 only, but don't say why.  I am under the impression that the 6 and 8 are swappable in a Commodore, so why wont the kit work on an 8 cylinder?
    If your engine is 48-52, the kit will work.
  • I did call Randy Mass.  He is checking into it, but didn't know.  The engine is a 1950. so this is encouraging.  

  • Ol racer said:
    supersix said:
    What. Arb are you using ? Thanks,Dave

    I use a 600 CFM Holley. I purchased Trans Adapter's from both Randy Maas & Danny Spring a long time ago then locally 'Indexed' a Hudson Flywheel to accept a GM Torque Converter. The center hole had to be enlarged for the Converter Hub too, Today they may have a Flex plate available. The Hudson Hydromatic Starter works fine.

    /

     Note:                                                                                                                                        GM 200R & 700R4 Overdrive requires a 'Throttle Pressure Cable' to control shift points to prevent burning up the Trans. Economical Universal Cable Kits are readily available online...


    Terraplanecoupe asks:  What is the thickness of the adapter plate ?  If you bolted a gm torque converter to a flywheel,  did the converter then engage the pump in the trans correctly?  I the hydromatic starter different than a stick starter and why did you use it?  Will Randy still sell the adapter plate separate from the rest of the kit.?  Thanks for the info.  


  • 50C8DAN said:
    Call Randy Maas and ask him, he would know if it fits or not.
    I did call Randy Mass.  He is checking into it, but didn't know.  The engine is a 1950. so this is encouraging.  
    Update 8/27/19---Randy responded that the kit will fit on my 1950 eight cylinder engine.