transmission and gear ratios? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

brizzle86 · 07-25-2015, 10:22 PM

Considering keeping 235 and having 700r or turbo 350 mated to it.
How hard would it be to adapt these trans to the 235? Adapter kit
Which be the best for speeds up to 70mph if possible with the 235?
Which gear? Just cruising on weekends.
Which rear end? Would like 5 lug axle.

Thanks

53 292 · 07-26-2015, 12:00 AM

We have a 2004R (overdrive) bolted right up behind a 292 with 3.42 gears in a 12 bolt and it does just fine at around 70mph.

Keith Seymore · 07-26-2015, 07:50 AM

I would recommend a 3.73 rear axle with the overdrive; 3.42 without.

K

**mr48chev** · 07-26-2015, 01:41 PM

Info on the trans adapter here and a good explanation of what you are looking at. I'd think that the 200 trans may be more desirable than the 700 in this setup.

http://www.langdonsstovebolt.com/tec...ission-update/

Trans adapter page http://www.langdonsstovebolt.com/sto...=0&sort=normal

OrrieG · 07-26-2015, 06:29 PM

th350 is 1:00 in 3rd gear same as stock 3 and 4 speeds, or PG or Hydro it you have that, so no gain in reducing highway rpm with original rearend. Here is a table that lists gear ratios, 700R has lower first and almost same OD in 4th as a 200R. Something I noticed in the little table at the left bottom 700R creates twice the HP loss(70) as a TH350 (35). I have always heard that manual transmissions have a loss of 20-25 hp.

07-25-2015, 10:22 PM	#1
brizzle86 Registered User Join Date: Apr 2015 Location: Georgetown ky Posts: 23	transmission and gear ratios? Considering keeping 235 and having 700r or turbo 350 mated to it. How hard would it be to adapt these trans to the 235? Adapter kit Which be the best for speeds up to 70mph if possible with the 235? Which gear? Just cruising on weekends. Which rear end? Would like 5 lug axle. Thanks __________________ 1947 Chevrolet 3100 3 window, 81 camaro clip, ls2, 4l60

07-26-2015, 12:00 AM	#2
53 292 Registered User Join Date: Sep 2010 Location: Salinas Ca Posts: 104	Re: transmission and gear ratios? We have a 2004R (overdrive) bolted right up behind a 292 with 3.42 gears in a 12 bolt and it does just fine at around 70mph.

07-26-2015, 07:50 AM	#3
Keith Seymore Registered User Join Date: May 2009 Location: Motor City Posts: 9,226	Re: transmission and gear ratios? I would recommend a 3.73 rear axle with the overdrive; 3.42 without. K __________________ Chevrolet Flint Assembly 1979-1986 GM Full Size Truck Engineering 1986 - 2019 Intro from an Old Assembly Guy: http://67-72chevytrucks.com/vboard/s...d.php?t=342926 My Pontiac story: http://forums.maxperformanceinc.com/...d.php?t=560524 Chevelle intro: http://www.superchevy.com/features/s...hevy-chevelle/ Last edited by Keith Seymore; 07-29-2015 at 12:29 PM.

07-26-2015, 01:41 PM	#4
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,711	Re: transmission and gear ratios? Info on the trans adapter here and a good explanation of what you are looking at. I'd think that the 200 trans may be more desirable than the 700 in this setup. http://www.langdonsstovebolt.com/tec...ission-update/ Trans adapter page http://www.langdonsstovebolt.com/sto...=0&sort=normal __________________ Founding member of the too many projects, too little time and money club. My ongoing truck projects: 48 Chev 3100 that will run a 292 Six. 71 GMC 2500 that is getting a Cad 500 transplant. 77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around.

07-26-2015, 06:29 PM	#5
OrrieG Registered User Join Date: Jun 2006 Location: Idaho Posts: 8,800	Re: transmission and gear ratios? th350 is 1:00 in 3rd gear same as stock 3 and 4 speeds, or PG or Hydro it you have that, so no gain in reducing highway rpm with original rearend. Here is a table that lists gear ratios, 700R has lower first and almost same OD in 4th as a 200R. Something I noticed in the little table at the left bottom 700R creates twice the HP loss(70) as a TH350 (35). I have always heard that manual transmissions have a loss of 20-25 hp. __________________ 1959 Chevy Short Fleetside w/ 74 4WD drive train (current project) OrrieG Build Thread 1964 Chevelle Malibu w/ 355-350TH (daily driver) Helpful AD and TF Manual Site Old Car Manual Project



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