Engine / Transmission swap - explain it to me like I'm 5

[hjl]

I recently picked up a 71 2WD Blazer. I had set aside a certain amount of money to buy it, and only spent half. So I've still got some left over, and I'm trying to decide how to best spend the money to fix it up. This will never be a daily driver, more like nice days, weekends, going for the paper or ice cream.

The body is decent, don't really need to do anything there yet, even though I might want to change the color eventually. I really want a custom roll bar, but that can wait, too.

It looks like it has the original 6 cylinder engine and three speed manual transmission. When I first drove it I thought I might need a carburetor rebuild, but now that I've driven it a lot more I think both the engine and transmission might be nearing the end of their life. So I started reading threads about engine and transmission swaps, which is dangerous to my wallet.

I can't do this work myself, but I've found a couple local mechanics with very good references who might take it on. I want to understand the process, and get a better idea about the amount of labor involved.

Can someone explain it to me like I'm 5? Here's what I've learned by reading threads on this forum:

1) A nice crate motor, automatic transmission, and various other parts needed can be purchased for around $3,000. Is that right? I looked on jegs.com for those numbers.
2) There's things attached to the frame called crossmembers which support the engine and transmission. I would need a new crossmember to support the automatic transmission, and the old crossmember removed. I would need new engine mounts to support the new engine. Is that right?
3) A torque converter fits in there somewhere, I think it's attached to the flywheel of the engine on one side, and the input shaft on the transmission on the other. Is that right?
4) I'll need a new or modified drive shaft?
5) I'll need a way to shift, either a new steering column with automatic shifter, or a hole in the floor with shifter sticking through? Does it make a difference?
6) The new transmission has fluid which needs to be cooled, which might require a new radiator if mine doesn't support cooling a transmission. Is that right?
6) What major things am I leaving out? I guess things have to get wired up differently.

Considering all of the above would take me close to 6 years, I have no idea how long it would take a skilled mechanic. Can anyone give me a very rough estimate on hours? Am I correct in assuming that rebuilding my current engine and transmission would be similar in cost, maybe slightly less?

Thanks in advance, sorry I wrote a novel.

[rsavage]

Charlie,
If it is an original 6 cylinder 2 wheel drive Blazer you might want to rebuild what is in the truck and keep it original. I would first have what you currently have checked out. Has it been tuned up? Plugs, wires, points, condenser, filter and maybe a carb rebuild? You could have your guy do a compression test and get an overall picture of present health. A 250 3 spd is never going to be a speed demon but if it is good shape, can run very well. I have never done a six to an 8 conversion on one of these, but if you do, to make it cleaner, i would change out the steering column to an auto column as opposed to an aftermarket shifter. You have covered a lot of what you will need. In addition a V8 shroud and an auto radiator, starter, flexplate, accessory brackets, pulleys, water pump, fan for a V8, auto trans linkage and lots of bits I am probably forgetting - I am sure others will chime in. Good luck in whatever path you choose. Rick

[4oldcars]

A year and a half ago I bought a 71 2 wd. I wanted to do exactly what you described. I too am not a mechanic, but retired and able to do most of my own work. Today it sits in my garage on jack stands as it has since I bought it. Thank you "Murphy". I have had many cars - street rods, classics, etc. I have never met so many dis-honest people as I have since I bought this one. No reflection to anyone on this site. People here are great. I once was so upset with it that I posted it here for sale at a very low price just to get rid of it. After a week with NO responce I deleted the ad. I'm still working on it and determined to drive it before I die. Good luck.

[RustyBucket]

A badly rusted or bashed up V8 auto truck that was pretty much unmolested would be a great donor for your purposes. You see 'em that aren't worth restoring pretty cheap. You'd get mounts, brackets, pulleys, probably power steering, an auto shift steering column, trans. cooler lines, crossmember..... maybe even a useable engine. OR buy your crate motor and find you a reputable guy to assemble all the pieces. For me, I'd leave it standard shift and run the 3spd. or buy a 4 or 5spd trans. You've already got the clutch pedal, Z bar, & bell housing. I like stick shift toy cars and trucks.

[hjl]

@4oldcars:

Sorry to hear you've run into so much trouble. I can honestly say that I have been lied to by everyone I've ever bought a car from, including some members of my immediate family! I guess I should count myself lucky that mine's on the road. Good luck.

@rsavage:

Thanks. It's with the mechanic now, and he's going through everything you listed. I hope he's going to tell me that a tune up and carb rebuild are all it needs.

I dropped it off this morning but it rained all day so he had to keep it inside and couldn't road test it. The sun came out around 4pm, I'm working the night shift so I start driving to work at that time. I go right by his place on the way to work, and he turns in 4 cars ahead of me. He had a huge grin on his face...but maybe he was laughing at me for buying it in the first place.

@RustyBucket:

Thanks for the advice, after driving it a little more the last few days I'm leaning towards keeping it stock, if possible. Now, I just need to decide on a paint color...I'm leaning towards black on black:

Black 72 Blazer

Of course, mine will never look like that, but I can dream.

[NTR72GMC]

First off, why do you want to put a rollbar in a 2wd blazer? I'm not trying to be rude or make fun of you, but I've seen a few 2wd's with them and the just don't look right.
Second I agree with rsavage on checking out the stock inline 6 and seeing what's going on with it. The fact that it's a factory 2wd with a stock inline 6 might make it a little more rare. (But I would put an automatic behind it as well)
Personaly if It was my blazer the only things I would do is clean up the motor (maybe rebuild) and every thing around it, and bag it (lower it). Don't get me wrong it's your blazer do what you want with it the most important thing is to enjoy it.
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[bouncytruck]

I'd look into fixing the stock 6. It doesn't sound like you're looking for a street machine and doing a v8 swap will end up being a time/money pit. The stock 6 should be a good runner.

I'd put some custom wheels on it and put lower it (air ride if you have the $). Then, drive it for a while and enjoy it before you worry about paint.

[RustyBucket]

hjl, please post some pictures, let's see what you got... ALWAYS like to look at Blazer/Jimmy pictures, as well as trucks, cars, planes, girls, guns, boats, motorcycles.....
Here's my rusty 2wd Jimmy the first time I took the top off. NOTE: I think the roll bar looks goofy in the 2wd., jus' my opinion... I backed the Jimmy under my lift and strapped the top to the bottom of the lift. I put the lift all the way up and it lifted the top off, then I set the top on my pop-up so I could move it around.
Oops, just noticed my avitar picture show the roll bar better than the one I posted if you click it

[SamMargritz00]

you could always do a 5.3/4l60e swap. junkyards have those for CHEAP. Ive been working on mine for 3 years. almost done. but the reason for 3 years is because i can only work on it 4-5 months out of the year cause i farm and the crops come first.

[hjl]

@RustyBucket: Pics are here: I got one. Your Jimmy looks sweet!

Thanks for the replies, I appreciate the answers and honesty. I guess a roll bar might look goofy, I was just thinking if it would be a little but safer if I want to put my kids in back. I'm kind of paranoid when it comes to safety, when they were toddlers I had gates at the top and the bottom of all my stairs.

My engine just got a clean bill of health so I'm keeping it. Going to drive it all summer as is. When I take it off the road for the winter I'll look into maybe paint or an automatic transmission or something else. I would like my wife to be able to drive it, she probably can't handle the manual.

[RustyBucket]

MIGHTY NICE '71!!, don't how I missed your orig. post about it. My Jimmy is a 20-footer, no, make that a 30 footer at best like my sig. says.