200R4 vs 350 Turbo

Hello everyone,

I have some experience with 700R4's and I currently have one on the back of a 4.3 in a 1949 chevy truck. I am not a mechanic...I just piddle when I can.

I also have a 1954 chevy panel truck and I just purchased a 305 engine and trans from a family member to go in it. I was told it was a 350 Turbo but when I went to pick it up it looked more like a 700R4 with the electric plug for the lockup.

The engine and trans has never been unbolted so it is bone stock with an aluminum intake etc...It apparently came out of a 84 El Camino and I looked online and I believe it is a 200R4.

My question is, I also have a rear end I plan to install in the truck which has a 308 gear I believe. I spun the wheel and counted the yoke and that is what it comes out to. I intended to use a 350 Turbo but now I do not know how a 308 will work with the 200R4. I know a 373 gear ratio is best for overdrive so can anyone provide me with their opinion.

I got the rearend for free and it already has new brakes and drums etc...so I hate to swap to match this transmission so if a 350 Turbo works better I can do that. Just need some advice.

Thanks for your time,
Knothead
Ohio


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Well if it was me I'd go with the 308 rear and 200r. With the price of gas that combo should get stellar fuel mileage. like in the 23 to 24 mpg range. Now you could up the rear end ratio to 3.55 and get like 19 to 20 mpg and still have reasonable performance. But any direction you go use the 200r better 1st gear ratio than the th350, and better fuel mileage. Good luck what ever you decide. Brian

Not absolutely positive, but I believe all Camaros of that vintage had a 700R4.
The pans are shaped differently, so you can tell them apart. BTO, TCI or CK can help with the ID...
I have a 200-4r and they only came in G-bodies like the Monte Carlo, Buick Regal, etc. 700's had a very low 1st gear (3.06), so would work better with 3.08's to get the truck moving. OD is .70, I think, vs .67 on the 200.

Here is a photo of a 200-4r. It is a Buick type of bell housing, the trans you would have is a multi-bolt pattern on the bell. Notice there is NOT a removable tail housing.

I'd run the engine and 200-4r trans.

__________________
At the Bonneville Salt Flats, first gear is known as 130 mph.

In order to make sure which transmission you have, go here and then compare

http://go.mrgasket.com/pdf/trans_id.pdf

OK, for some reason I read Camaro instead of El Camino. It's a 200-4R.
Nothing wrong with that, mind you. Builders are claiming 700 HP capability when properly modified, so in stock form it's fine behind a 305. I've got one in my '67 406" El Camino with 4.33's and that OD is a godsend. Soon's it quits RAINING around here, I'll get to thrash it....

Thanks everyone for your help. The picture from Crosley looks like it but I will look again tomorrow in the daylight...Thanks for the other websites as well. I will pass that on to some of my friends. I just remember thinking man this does not look like a 350 turbo and it doesn't look like the 700R4 I had as well. It is just one big trans...

Just so I know....are there any 350 Turbo's that have the plug for the lockup unit or as long as you see that plug you know it has to be a 200 or 700 R4?

Thanks again guys for your help it is so nice to post this in the middle of the day and come back in the evening and have all these answers....

Knothead...

Hi Guys,
They did make lock-up 350's and they have a square plug just like 200 and 700,a quick way to tell 350 from 2004R is the case,350's have a bolt on extension housing at the rear of the trans (4 bolts) 2004R has a one piece case. Hope this helps.

I run a 3.08 gear with a th400 (1:1 high gear like a th350) with 28 inch tall tires. And I wish the rpms were lower going down the highway. 75 mph is around 2800 rpms which is a little buzzy with a small cam'd BBC. With a 0.70 OD that would drop to 1950 rpm. Maybe a little too low unless you have a very short duration cam or shorter tires (2100 rpms with 26's).


A 3.55 would be the best mix between power and highway rpms with a 0.70 OD. 2250 rpms at 75 with 28 in tall tires. 2400 rpms with 26 inch tires.

We recently installed a 700r4 into a 69 firebird, his final drive ratio was in the .260 range. He is happy with how his car performs and loves the fuel mileage.

The 2004R would be a good choice, all around, for this vehicle.