Many brake kit vendors offer brake rotors in either 4.5" (Ford/Mopar) and 4.75 (small GM). Shouldn't be a problem to order what you need. Ray
Agree, don't overthink this and psyche yourself out. Just get a rearend that is correct width and a good gear ratio to match your 700R4. Like the popular 3.73 geared Explorer rearend, it is an 8.8 and plenty strong. Many are limited slip, and newer ones are even disc brakes. If you can't find a Explorer rear for cheap around you, something wrong with your searching, Explorers are everywhere. A Granada/Monarch rearend is also a good choice, but those cars are getting more scarce in the yards - make sure it is a 8-inch or 9-inch, not the smaller 7.5 or whatever that one is. GM choices as listed by several previous: 67-69 Camaro/Firebird, 68-72 Nova and it's clones, S-10 4x4 (2wd is too narrow), 55-57 Chevy. Then get front disc kit to match the bolt pattern of the rearend. Put it all together and measure for a driveshaft, then go cruising.
TBilbrey64, Just to keep facts straight, I have two 1951 Chevys, both have later model 235 engines. One has the stock 3 speed trans/torque tube combo, with the 4:11 gear ratio. Certainly, it will cruise at 60 to 65, without ANY screaming. It has done this 65 MPH travel, for the past 14 years of my ownership, without any negative incidents. You must remember, when these cars were new, there were NO interstates, only 2 lane roads and NO 65 or 75 MPH speed limits. Cars were designed and manufactured, with those available road conditions in mind. The other '51, engine pictured in avatar, has a 235, '59 Chevy 3 speed manual,with overdrive and a 9" Ford rear end, with a 3:50 posi. When the standard, torque tube rear end was changed to a FORD, open drive line, there WAS welding required. WELDING IS REQUIRED to install the new perches to the REPLACEMENT rear end housing. When doing the 230 conversion (different family than the 216/235..... plus the 230 is physically LONGER) and the 700R4, you will face different engine mountings, a possible radiator relocation and a different tranny crossmember. If you have the know how and mechanical ability to deal with these variations, then the rear end swap will be the easiest part of the overall job.
Carl............I am an admirer of your droll sense of humor, but come on....neither the Lincoln Highway nor Route 66 can be considered "Interstate" highways as designed and designated by the Eisenhower administration and first in operation in 1959. Did the subject highways go from State to State ? Of course.....but I am old enough to have traveled on Route 66 in it's original form and it was a far cry from I-55, I-44 and I-40. Route 66 and, perhaps even more so, the Lincoln Highway, traveled over hill and dale, through small towns and cities, were curvy, hilly and not given to long legged cruising unless one was in the deserts of the southwest. Ray
In 1913, built or plowed out, the Lincoln Highway was not much more than a "path", going from NYC to San Francisco. A 20 MPH road, at best, where you had to measure water depth, before proceeding. Yet it was labeled "highway". Should have been labeled "a challenge". My comments concerned '51 Chevys and "Interstates", as in Dwight David Eisenhower Interstates. There were no Interstates in 1951.
Well, I found a 1957 rear end about a hour north of me for $200.00 and I'm going with that. I already have the 700R4, and I'm picking up 230 over in Columbus on Sat. I have found mounts for the motor, and a crossmember for the tranny that will require a little fab work. My best friend is an excellent fab guy, and can make me anything I need. I like to do as much to these projects as I can, but when it comes to fab work I'm lacking, and I know it. And when I've got such a good source of quality information as all of you guys are I can't go wrong. As I move forward with this build I'll plenty more questions I'm sure, and I really do appreciate you guys taking the time to help me out. Tim
Yeah, the Lincoln Highway was a stretch, but Route 66 was a fully paved, interstate highway, by 1938, extending from Chicago to Los Angeles. It may not have been part of Ike's system but it was there. Ask all of the dustbowl Okies
Keep in mind the physical difference in the length of the 235, as opposed to the length of the longer 230.
I know the 48 is a different animal than the 41, but my 250 in my 48 did not require moving the radiator. I used 70 chevy pick-up engine mounts, modified to fit.
From my experience with old chevys, when you change one thing, you end up changing everything! The swap described looks like one of those. I see the front fenders, grill, hood and core support coming off and on a couple times for engine placement/engine's side motor mount fabrication/check for fan to radiator clearance. If memory serves me, 41 Chevys where 6 lug hubs. Changing rear to 57 will switch to 5 lug (good) but if fronts are to match, front hubs need to be changed as well, may as well go to discs. But while you're in there why not get rid of that archaic knee-action suspension and make the disc conversion simple by swapping in a MII style front suspension? Then before you hit the road, maybe consider the implications of your final drive ratio. If the 57 diff is a 3.36, 3.55, 3.73, does the engine/trans have the torque to utilize a .74 overdrive. Even a 3.73 ratio in overdrive results in a 2.75 final. The though the th 350/400/700R4 is a direct bolt up, the short stroke 230 was never designed to utilize overdrive automatics. This may require a gear swap into the 57 housing a ratio closer to 3.90 or the low 4s to effectively use the OD. With all that sorted, now you get to deal with E brake interface and trans throttle valve linkage to 230 carb setup. Are we done yet? Wait, a 230 won't start on 6 volts. I just want you to be prepared for what you're up against. Best regards and good luck with all your endeavors, KB.
Thinking of the 41 to 48 era, there may ben enough room to accommodate the additional length of the 230 engine. More of a "peak" to the front end. Now, my '51 has a "flatter" front end, so the additional 2" or so, of the 230, can be problematic. Look at my album, you can see the tape meaure in there, with the shortened water pump on the 235.
Ok what is the length difference 235 vrs 230? Langdon says Chassis Engineering has motor mounts for the 230. I plan to go with disc brakes on the front so I have 5x4.75 all the way around, and when I bought this car the first thing I'd plan to do is rid myself of the 6 volt system.
See #46 on 230. Read this post, as well. http://www.chevytalk.org/fusionbb/showpost.php?post/2341846/ Properly maintained, with the CORRECT sized battery cables, the 6 volt system works well. My BLACK '51 still has the 6 volt system, works well for me.
I went ith 12 volts. Brighter lights at night (I drive mine at night a lot, and we have deer), better and easier radio selection, etc. bobg, what is the engine in your avatar?
Belair, the engine in my avatar is a 1961 235. Engine is bored .080 over, cam is a Patricks 3/4 cam, intake and exhaust are jet coated Fenton units, head is the "848" variety, carbs are Rochesters. There are two '51's in my album, both are still in my possession, one is black, one is dark blue.. You can see the "avatar engine" in the dark blue 1951.
If you still have the 216 or 235 in your car, look at the clearance from the fan bolt heads to the radiator. Assuming the rear of the valve cover is CLOSE to the firewall, how much clearance are you seeing? You may have no problem fitting the LONGER 230 into its new home.
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