Inliners International Forums General Discussion Engines 250 in a 48

I am putting a 250 with standard transmission in my 48 chevy, has anyone done this, and what problems did you run into.Im going to have a three speed on the floor and am thinking i will have problems with the original seat. Also will the 250 clear my radiator. I ordered the engine mounting kit from chassis engineering so i can bolt the 250 in my 48.If anyone has any ideas that will help me please let me know. Thanks all.

I originally had a 250 in my '40 and it wii be going back in. I used a side mount similar to Chassis Engineering and they worked good. The trans is a very tight fit to the floor and we made up a flat plate mount for the trans. I used the shifter off of an early '80s Malibu as it mounts at the front of the tail shaft but seat clearance is still very limited. Possibly a S-10 5 speed would move the shifter ahead a little more. I also used the original clutch fork in the later bellhousing as I am still using the original pedals up thru the floor. The rad was very close so I had the straps remounted to set the rad ahead and used the thinnest spacer I could find for the water pump. Headers work good. Mine has a Must II front end in it with a rack.
Good Luck with it. I would imagine you will get a few more replies as well from other members who have done the same.

Thanks for the reply, I have solved the shifting.Also i am using hanging clutch and brake pedals. I really dont want to move the rad.I thought about removing the fan blades, and just run an electric fan, but dont know if this will cool enough.Also need to find a rear end that will fit.

Kip besides what Don has mentioned and what you have already considered there are a few other things to keep an eye on. The 250 is about 2 inches or so longer than the 216. Moving the engine as far back as practical helps and moving the radiator as far forward as it can go also helps. After that the next situation is the fan will be lower on the radiator with the 250 than with the old 216. This isn't the most effective place for it and it works better when pulling through the upper area. I solved this on my 37 by using a 14 inch electric fan from Parr Automotive and mounting it up just under the tank. They had the thinnest 14 inch fan around and it cools very well.

The other area of concern is you will be using firewall mounted pedals. That is fine but keep in mind those firewalls were never intended to take the stress of pedals being pushed against them. Double up the firewall with a piece of .093 to 1/8 inch thick plate on the inner side to add strength. A few inches all around beyond what it takes to mount the pedal assy is enough. You can either weld it in place or use the pedal brackets mountin bolts to hold it, welding a few 1/2 inch long tacks around the outer edge is better.

A hydraulic clutch and brake pedal combination kit works very well and we did a 36 Chevy this way. Ended up using the bellhousing and slave cylinder assy from a Camaro / Corvette / S10. Any will work as long as it was for the V thingys either the Small block V8 or a 4.3 V6 as the backs of the blocks are the same as the 230 - 250 - 292 family inlines.

As far as a rear end we used 57 Chevy rears in the 36 and 37 hung from Chassis Engineering rear suspension kits. The kit is a bolt in but we had to clean off the 57 spring pads from the axles and mount new ones in the correct location. The center bolt holes have to be drilled further forward on the new pads or the axle won't be centered in the wheel openings of the fenders. This is common and easy to deal with. Just make sure you have the weight of the car on the new springs when measuring how far off center you have to drill.

Good luck. I know you'll find it is worth the effort to do.

Mike

Thanks Mike, i got the engine installed today, and the clutch all hooked up.It wasnt as bad as i thought. I am not going to run the original fan, but am going to install an electric fan with a thermostat. If new cars can work with this i guess the 48 should work ok.I need to lower my trans mount a bit, as the tailshaft is to close to the floor pan, and i think my u-joint will hit. I hope this does not put to much of an angle on my engine. No one could tell me what angle the engine should sit at.I was told that a 71 Nova rear end is the same dimension as thr 48, so i might check that out. Im sur i will have more questions later. Thanks for everyones help.

Kip, I believe the offset on the rear spring pads that Mike was talking about is 1 3/4" to properly centre the rearend. I was always told to put a level across the air horn of the carb you are using (the flat surface where the air filter will sit) and to have that level when you are making up mounts. Try that and see how it works out for you. What are you using for a steering column? I used a mid 70's Camaro in mine and the length was good.

I think you are right Don. 1 and 3/4 sounds about right if using the original springs from the torque tube rear end. With the Chassis Engineering kit on my 37 it ended up being only 3/4 of an inch off dead center. This obviously is because the center bolts in the springs do not end up exactly in the same place as the original Chevy springs.

Kip as far as the carb being level Don is right and you'll have less carb headaches. Generally the engine itself tilts slightly down in the rear about 2 degrees with 3 as the max and the intake manifold sits at an angle to the engine. This needs to be figured at ride height and an easy way is to have the chassis on jack stands or whatever and shimmed to get the frame level front to back and adjust for your couple of degrees from there. When mounting the rear axle have the weight of the car on the springs by supporting the car under the springs near the axle location with jack stands, leaving enough room to work at the axle location. Place the spring pads over the center bolts and drop the axle housing onto them. Get it centered side to side and using an angle gauge rotate the housing up or down until the angle of the machined face where the cover bolts on is the same as the angle of the face of either the bellhousing or the trans tailshaft where the seal is. Always be sure to check these angles from a machined surface and not a cast area. This ends up with the trans output shaft parallel to the pinion shaft and gives the best life for the u joints and no driveline vibrations. Once you have triple checked everything I find it easiest to tack weld the pads to the axle tubes and then pull it out and onto the bench for the finish welding. A few 1/2 inch long welds on each side of the pads is enough. Go slow here or you can easily distort the axle tubes.

For racing the pinion angle is often nosed down several degrees to compensate for spring wrap under extreme torque conditions but that's not what you want in a street driver.

Hope this helps you a bit.

Mike

Thats neat, Mike. I never realized to match the diff cover housing to the tailshaft and bellhousing. I guess we never stop learning if we take the time to read and listen to people. Good Luck Kip, you should have enough info now to keep you out of trouble but if not, ask more questions and you will get answers from guys who have been there and done that.

Thanks guys, what a big help you all are. Im using my stock steering columnm but need to find a stock steering box for the 48. Mine is shot, and i cant find anyone who sells the worm assembly for it.