Newbie 250 to 350 swap questions-HELP!

[bueller60]

Hi, great board. I recently bought a very clean 68 c10 stepside with a 250/3speed drivetrain. The 250 died and I got a great deal on a 350/TH350 combo from a 69 Camaro. I'm new to these trucks and I have some questions that I hope you guys can help with. I'm have some mechanical skills and less computer skills.

I've read all of the threads that I could find regarding the swap and the engine position (I6 rearward vs V8 forward). My TH350 measures 28 inches front to rear while my original 3 speed measures 23 inches. I have a one piece driveshaft. Here are my questions:

1. Should I invest in some V8 motor stands and move it forward and if so, is there any possible way to get 5 inches?

2. I've read that I need to cut out my bellhousing crossmember and find a TH350 crossmember to replace it....does it matter what year?

3. I have no shifter and no shift linkage...should I attempt to find factory stuff and if I do, is it a big hassles to mount?

4. What color should my tranny be to be factory correct? It's chevy orange now but it's out so I could easily paint it.

Thanks in advance and sorry for the long post.

[ThatOneBlue67]

Well, everything bolts up in place of the inline six (motor wise). You can move it forward the extra 2 inches or leave in the I6 position. It really doesn't matter, except that when it comes time to order radiator hoses, you'll have to make up for the extra few inches back from the radiator.

I do not recall original tranny colors, but orange is the correct clor for a Chevy motor.

SHIFTERS:

There are a few ways to go bout this. You could buy a 200 dollar BM shifter (which work great) and cut a hole in your floor. It bolts up and comes with a nice boot, shift indicator, and base so it won't look trashy or anything. Great racign shifters and it is a cable system.

You could slightly modify things and use an auto transmission floor shifter out of another car and slightly modify to work.

Or you can find a column out of a 67-72 Chevy truck that was for a TH350 transmission. You'd have to replace the ENTIRE column in order to have an automatic tranny shifter on the column. **I did this swap for three reasons. It was cheap (junkyard parts), it was stock, and it was practical. Using a floor shifter while your bench seat is full of people is a pain in the back.

[motocrosschump]

or you can leave the 3 speed in place and bolt the 350 to it.

[Ole Blue 68]

Originally Posted by motocrosschump

or you can leave the 3 speed in place and bolt the 350 to it.

You could do that but I think it's worth the extra trouble to dump that 3 speed. I kept mine and wish I hadn't.

[flatbedchev]

I second that. I have my 350 in the inline position with the saginaw 3 speed. Now I'm wishing I would have swapped the tranny for something with higher gears

[Classic Heartbeat]

My recomendation is to do it right the first time. Finding parts for these trucks at time can be a bear when it is the factory application, it's much worce when not. I say get the towers, auto trans crossmember, auto linkage, steering column, and lengthen the driveline. If it were me I would also use the short water pump on the motor, alternator bracket, power steering pump and bracket, etc. When done if someone that was to look under the hood they would be hard pressed to tell that it was an original in-line 6 truck. Set it in the 6 spot and they will spot it immediately. JMO... WES www.ClassicHeartbeat.com

[motocrosschump]

I guess I just like old vehicles to feel like old vehicles. The only way I would take out my 3 speed, is to replace it with a Muncie. To Them their own I guess.

[roadking]

IMO,
invest in the v8 mounts the engines look so much better in the factory position. before you decide go out and look at some trucks with v8 in the i6 spot, they our crowded at the firwall which can make it tight with a HEI. used parts for this conversion are fairly easy to come by with the help of forums like this. go with a tranny with overdrive, i would if i had it to do over again.

[PanelDeland]

If you use the th350 with the stock gearing you will be spinning 3.73 to 1 rear gears.Most auto from the era used a 3.08 and the newer ones usually use a 3.42.This is just info to help you plan and understand the differences other than obvious physical that you will encounter.Someone should be able to post a link to a gear and tire calculator that will help determine your final drive RPM's.I had it but forgot to move it to my new computer.