I have an '82 F100 Shortbed pickup with 300 six and C6 transmission.
I am looking at a low-mileage 302 engine out of a '77 Lincoln Versailles.
What is involved in swapping the V8 for the six?
Will the V8 bolt up to my C6 transmission?
Do I need to change motor mount perches?
What do I do for exhaust?
Thanks,
Dave in Liverpool, NY

 

I am no expert but what I have seen posted the 302 should bolt up to your C6 only thing I am not sure on is convertor to flex plate bolt up?

Yes you will need to replace the 6cly free perches with 302 ones.

Exhaust is up to you what you want.
I am thinking a stock Y pipe for your year truck would work but don't know if the cars manifolds are the same as the trucks?
You could go headers. Don't know if they make shorty headers and if they do they may use the stock Y pipe.
I am sure they make long tube headers for your truck.
Dave - - - -

 

Not to question the swap - it is your truck & decision - but why the change?

The 300 six is a great truck engine with good potential for improvements to power if that's what you're after. If it's wore out and the 302 is free or cheap, then so be it.

Other than that, what FF2 said is good guidance. To add to that, you'll have to consider modifying fuel lines to the mech pump (might not be a big deal). Throttle cable from the 300 may be the right length so would hook up OK. DS2 harness should also hook up to 302 distributor; there are the other sensor wires (oil pressure, temp) than may need to be adjusted.

But yes, it should bolt up to the C6 OK, even the torque converter. Just look at specific engine mounts and deal with the exhaust are probably the biggest factors.

 

Before getting into the specifics of the swap, I want to second the question of WHY? As said, the six is an excellent truck engine, and provides a lot of torque at low RPM - right where a truck needs it. The 302 is a high-winding engine that, with the right mod's, can deliver horsepower but not torque and is best suited for lightweight vehicles. So, why?

As for the swap, in addition to what's been said you'll need a truck 302 oil pan as the cars have the sump in the wrong spot. And you'll need a V8 radiator as the inlet and outlets are reversed on the six. And, info on the engine stands is here: Engine Perches - Gary's Garagemahal.

 

The 302 will bolt up to the C-6 trans. You can use the torque converter too.
You will also need:

Flexplate for the year of the engine, If it really is a '77 engine, you will need the 28 oz. imbalance. The 302 changed to a 50 oz. imbalance in mid-81. If you use the wrong one, you WILL be replacing bearings and possibly other parts.

Throttle cable, the I-6 and V-8 are different

Frame perches

Rubber motor mounts

Radiator

Radiator hoses

Oil pan with correct pick-up tube (which will also require swapping out a main bolt to one that has a threaded stud on it for the pick-up tube to mount to.

Dipstick - If the engine has it in the timing cover, you'll have to plug that hole and use a pan-mounted stick.

Possibly a different trans dipstick - The V-8 ones swing out to the side farther to clear the head and valve cover.

Exhaust - If you can find a good Y-pipe and manifolds, or run headers with GOOD gaskets

Re-work the wiring harness so everything connects correctly.

It's more than a quick job. I do not want to discourage you, but if this is "just 'cause I can", or "I want a V-8", you may want to think about what others have said. Although the 302 is a great engine, I, personally would not have one in a truck if it was going to be used as a truck. If it's just a toy, go for it....or find a 351 and have the best of both worlds.

 

What he said!

 

And that was just off the top of my head.

Gary, we really need more smileys.

 

Yes, we do.

And, as we seem to get the same question over and over on swapping engines, it would be good to document what it takes, and do so in a format where we can update it as we realize we've missed something. What do you think about having a page or set of pages on my web site to do that? Then we could refer the person there and know that it represents the best info we have.

 

Guys,
Thanks for the detailed information. Sounds like an expensive change with few benefits. I have decided to keep the old faithful 300 six!
Thanks again for your help,
Dave

 

I think that's a great idea. I've done that exact swap before and with collective minds, I think we can get pretty in depth about the whole process. Maybe have a general thread to get all the valuable input on the swap, then transfer it to your site?

I'm going to have my engine out in the next couple of weeks ('86 w 351), and can get pics of rivets in frame mounts, fuel lines, etc.. if you want to go that far. Could also get pics of how we think the easiest way of doing things.

I'm also building a new engine (the reason for having it out) and could do a thread on how to check clearances (bearings, piston to valve, thrust, etc..) and step by step on building a V-8, then the install.

 

Sounds like we may have the makings of several web pages. I'll start a thread, or threads, and hope you and others will jump in.

 

I for one would find that website invaluable. I am finally back to working on the truck and have come to find the rear seal leaking considerably and I am down to 90 PSI ON CYLINDER 8. (1982 f150 302, c6). Since I am new to the DYI Truck game and don't have the right tools, I am looking at a four figure engine job. Might as well swap the 302 for a 351, change manifolds get the right flywheel and flex plate and be done with it. I would be willing to contribute any and all trials troubles and photos!

 

I'll take you up on anything you want to contribute.