Opportunity for a full powertrain transplant

[Zogbert]

I've got a 1972 C-10 (250 CID with three on the tree), that I'd like to use on the highway. It has a few issues. On any acceleration, and above 50 mph, the valves rattle like crazy. I've checked the timing (many times), burn premium fuel, and have experienced no real change. Also, the gearing is far too low for what I want.

I've got an opportunity to purchase the engine, transmission and rear end from a 1976 Chevelle Malibu with 55,000 miles.

A) Will this combination work in my truck?
B) Am I going to solve any issues?
C) Will I create more issues?
D) Is this complete sacrilege?

Thanks for any input!
Zogbert

[truckster]

Have you adjusted the valves?

In answer to your questions:

1. Yes, it will work. You're going to need to modify your engine mounts and there will be a bunch of other stuff that you'll need, but if you've got the donor car you can use the brackets and accessories from that. You'll also need to swap the column or install a floor shifter for the auto trans. Your rear end is likely a 12 bolt and the Malibu will have a 10 bolt. You'll need to weld on new perches to mount it in your truck. You're probably also going to have to have a driveshaft shortened or lengthened.

2. You'll have more power available to you. I can't say if you'll solve any issues since I don't know what condition the Malibu drivetrain is in.

3. Yes, you'll create some issues, most of which I've already mentioned.

4. Not a complete sacrilege. For that you'll have to reference the question about putting a Ford 4.6 into one of our trucks.

[71meangreenc10]

Id keep the 12 bolt and re-gear it.

Engine trans mount and engine perches have to be replaced, if you want it to not ride the firewall, not a good thing for HEI distributors, re-wire the HEI correctly. Drive shaft has to be lengthened if you put the V8 in the right place. Exhaust manifolds probably wont work on the truck. Get the right accessory drive pulleys off a V8 truck so it looks correct. Driveshaft yoke is ok as long as you don't have a 400 trans going in. Auto column and shift linkage, could be a few things I left out. I've done it. Not hard to do, lot's of folks here to help if you get into a bind.

Smitty

[Zogbert]

Thanks for the responses!

I'll adjust the valves and go from there. Sounds like the Malibu powertrain may not be the best option.

[Maximus]

I didnt see, but did anyone confirm this Malibu donor was actually a V8? (305 or whatnot?) the I6 was also an option in 76 malibu, no?

If your not set on an engine swap, there is probably alot you can do to wake up that little motor with tuning and possibly parts upgrades. intake swaps create their own challenges (with throttle linkage and such) but if you like the 6, dont give up on it yet.

[Zogbert]

It is an I6. I forgot to mention that. I really don't want to install a V8. Kind of like to keep the engine matching the VIN.

Thanks again for all the input. This site is the best!

[truckster]

Originally Posted by Zogbert

It is an I6. I forgot to mention that. I really don't want to install a V8.

That changes things. I believe the Malibu 6 is going to have the integrated head, which is different from your 6. The last straight-6 swap I did was an integrated head, and it was a pain in the rear.

You'll also lose some power going to an automatic transmission, and behind the 250 that's significant.

I wouldn't do it.

[Alex V.]

First, make sure your current engine is indeed worn out and not just in need of some good TLC. Secondly, I'd agree with others - if it isn't a V8 you're swapping in the only benefit the Malibu may be to you is a stronger engine, but possibly not worth the effort if yours can be revived. A stock six won't tolerate drastically lower gears than it came with - they turn 2,600-3,000 RPM on the highway and it doesn't hurt them. You just have to ackowledge that's how it was designed to work, and it probably won't do 75 without great protest. From the older 6 cyl. rigs I've driven, I'd much rather spin them at 2,800 at 70% throttle than 1,900 and wide open.

[Zogbert]

The transmission from the Malibu is a 3 speed manual. I was thinking of installing that. With what Alex is saying, I'm not going to change anything...just tune up the engine.

Thanks again for all the advice!!!!!!!!!!!!