CRG Discussion Forum

Camaro Research Group Discussion => Mild Modifications => Topic started by: 1969rs on February 13, 2019, 06:41:33 PM

Title: 67 Powerglide to TH350 conversion - what do I need?
Post by: 1969rs on February 13, 2019, 06:41:33 PM
Dropping a 350 crate motor in to my 67 Convertible. Old motor was 283 with Powerglide. The new set up will be 350 crate with mid 60's TH350 trans. I want to retain my stock 67 shifter. Found this conversion at Classic. https://www.classicindustries.com/product/sck105c.html

What else do I need? Do I need a different cross member? Will the drive shaft from the PG set up work?

Thanks!!

Rick
Title: Re: 67 Powerglide to TH350 conversion - what do I need?
Post by: Kelley W King on February 17, 2019, 03:05:41 AM
Since no one has replied I am pretty sure most all will work. Maybe driveshaft yoke will not but I think it does. It has been a while since I did one. My brother did a 65 vette from glide to 350 and then to Muncie with the same driveshaft and the vette crossmember is welded in so it worked. Now a 400 turbo is a different story.
Title: Re: 67 Powerglide to TH350 conversion - what do I need?
Post by: janobyte on February 17, 2019, 05:42:55 PM
Only thing I can think of is tail shaft housing lengths. Might be longer in the glide,might. Long in a 64 Impala, dont know camaros. Other then that it will bolt right in, same mount location.
Title: Re: 67 Powerglide to TH350 conversion - what do I need?
Post by: olddragracer on February 17, 2019, 07:40:18 PM
I have done many conversions from powerglide to TH350, TH400, and TH700 transmissions. I will try to remember what is required to convert a 67 powerglide to a TH350 transmission. You will need a correct filler tube and dipstick, a different flywheel cover, a throttle pressure cable, a cable mounting bracket [at intake manifold], misc. fittings to adapt the cable to the carburetor, a different vacuum tube and the shifter kit you have sourced. The flywheel may have a different bolt circle where it bolts to the crankshaft. Change was in 1986. You will need a TH350 with a 6 inch extension housing as they come in 6, 9, and 12 inch lengths. With the 6 inch housing the drive shaft should work!   I think you may have to move the crossmember rearward on the subframe and drill at least two holes to secure it.  With a little more work you could install a TH700 transmission. That would give you 3 similar gears plus a 30% overdrive making the car better for highway driving and improve fuel efficiency.   Good luck on you conversion
Title: Re: 67 Powerglide to TH350 conversion - what do I need?
Post by: 69Z28-RS on February 18, 2019, 01:18:11 AM
The 700R4 is LONGER and much heavier than a Power glide, but the 200R4 is the same!  and provides for the same (or better) OD capability, lighter weight, less internal loss, and is more than sufficiently strong for your 350 ci crate engine.
Title: Re: 67 Powerglide to TH350 conversion - what do I need?
Post by: olddragracer on February 18, 2019, 02:21:04 AM
The TH2004R is another 4 speed option. It is lighter and in my opinion is a better working transmission than the TH700R4. The work involved in converting to either of the 4 speed transmissions is about the same. However the cost of the TH2004R core and parts is usually much higher. There were fewer 2004R transmissions so it is often harder to find cores and parts. They are also much more difficult to correct the speedo reading and getting the governor to work with high horsepower in a light car.
Title: Re: 67 Powerglide to TH350 conversion - what do I need?
Post by: 1969rs on February 19, 2019, 01:19:41 AM
FYI, I already own the TH350, so the 700 is not an option.
Title: Re: 67 Powerglide to TH350 conversion - what do I need?
Post by: Kelley W King on February 19, 2019, 01:54:56 AM
If you are going to run much of a cam I don.t think you want overdrive anyway. I don,t think my L78 400 turbo with 355 gears would do well with overdrive.
Title: Re: 67 Powerglide to TH350 conversion - what do I need?
Post by: olddragracer on February 19, 2019, 09:54:19 PM
When modifying first generation camaros a high horsepower engine is usually the first change. An overdrive transmission, manual or automatic, is generally the next change. The rear axle ratios that work with the 4 speed overdrives and original 12 bolt axles are 3.55 and 3.73.  These combinations improve highway drivability and fuel efficiency. My personal preference is to keep first gens as original as possible,
Title: Re: 67 Powerglide to TH350 conversion - what do I need?
Post by: z28z11 on February 20, 2019, 03:32:13 AM
The TH2004R is another 4 speed option. It is lighter and in my opinion is a better working transmission than the TH700R4. The work involved in converting to either of the 4 speed transmissions is about the same. However the cost of the TH2004R core and parts is usually much higher. There were fewer 2004R transmissions so it is often harder to find cores and parts. They are also much more difficult to correct the speedo reading and getting the governor to work with high horsepower in a light car.

I disagree a bit with the availability of the 200/4R ( a little) in that they are a dual pattern Chevy/BOP bellhousing flange pattern, and came in a BUNCH of B-O-P cars and the Monte Carlo SS cars (as a heavier duty version) from the early 80's until the 700 (Chevy only pattern) made it's appearance, I paid $25 and $75 bucks for my cores, complete with converters. They are an exact match for the TH350 in length and output shaft, so you don't have to massage your driveshaft. You can build them to be stout trannies with the right parts, and control the converter lockup with a simple switching (adjustable) control box. A good Firebird friend of mine planted one in his '69 400 convertible, the thing will snap your neck off on shifting when you step on it, shifts firmly otherwise. Plus gets greater mileage than the former trans. The '86-'87 SS trans are the ones to look for in the junkyards, heavier duty input shafts and internals. JMO -

Regards,
Steve 
Title: Re: 67 Powerglide to TH350 conversion - what do I need?
Post by: olddragracer on February 20, 2019, 04:37:42 PM
The reason 200-4R transmissions are harder to find. The BOP cars are mostly front wheel drive and the rear drive cars are heavy station wagons geared for economy. Using one of these 200-4R's presents the problem correcting the governor and speedo. Units from Monte Carlo SS and Buick Grand National  are hard to find in my area. The 86-87's have furnaced brazed torque convertor fins which are important when installing the transmission in a high horsepower car. The 700R4 was used in cars and trucks making them easier to acquire. I would choose the 200-4R for a first gen Camaro and would be sure the shifts were firm but would not give my wife a stiff neck. I think I have gotten off track while trying to help with a poweglide to TH350 conversion. 

Title: Re: 67 Powerglide to TH350 conversion - what do I need?
Post by: 1969rs on March 02, 2019, 09:09:30 PM
Thx everyone!!
Title: Re: 67 Powerglide to TH350 conversion - what do I need?
Post by: 68L30 on March 26, 2019, 11:31:32 PM
I made the swap almost 34 years ago, as a 16 year Ol kid. Easy Peasey...get a kick down cable, dip stick, bend two cooler lines and add a torque converter cover,  youíre done. Donít over think it.. 😎

Steve