lindstromjd
Black Sheep
Does anyone have a good write up on what exactly all I need to modify to fit a 6.9 and C6 into a '78 F150 4x4?
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6.9 IDI in a '78 F150
- Thread starter lindstromjd
- Start date
it's not a drop-in due to the crossmember and the steering linkage, but it can be done. there's a couple guys who have converted trucks here, they do drop in every now and then.
dakotajeep
Patrolling
This is my dream body style with a diesel...good luck!
lindstromjd
Black Sheep
I'm hoping someone has done this and can tell me "do this, this, this, and this and the rest is simple" and then I can put it all together. I don't have a problem fabricating anything, as I'm pretty good with a welder. I just would like to know what I'm getting into without having to figure it all out on my own the hard way. 
I forgot to mention that the 78 is a Highboy short bed that originally had a 400 in it. Don't know if it makes a difference.
I forgot to mention that the 78 is a Highboy short bed that originally had a 400 in it. Don't know if it makes a difference.
bbjordan
Snow Monkey
Why a C6? Just cuz you got one?
lindstromjd
Black Sheep
Yeah; all this came out of an '86 donor truck that got hit really hard and totalled. The C6 the P.O. had just had rebuilt, so it's got less than 3k miles on it. The fun part is going to be converting it to a 4wd tail shaft though, because right now it's a 2wd... and I don't want to spend $300 for someone to do it for me.
CSARebel916
WMO Burner
I put a 6.9 in my 79 F-150 about 4-5 yrs ago. I dont have any pictures of the process, Im not one to like pics lol. The biggest problem I ran into was the motor mounts. I used to short side frame mounts, and modified my factory motor mounts. Also you will need to install a 3in body lift so the brake booster will clear the valve cover. As for cooling you will have to run electric fans, because u will have like no room between the water pump and rad.
I ran a divorced NP205 and zf5 from a 94 van in my current 1979 F150. I just set the motor/trans back a little so I can run the stock fan. The 3" body lift is a must I think or if anything will make everything go just that much smoother. As for mounts, I made templates out of cardboard once I had it where I was happy and used most of the stock 351M mounts that where in there originaly. lots of cutting and welding. Also the front cross member I took it down a few inches and capped it giving me about an inch of clearance from the oil pan. Lots of fun i tell ya!!!!! I just had it for first test around the block and so far so good. Also waiting for some guages before I take her a real road test as You cant fit the bigger rad without major hacking of the front end. At least I couldnt figure anything out.
papastruck
Full Access Member
Not to nitpick but a highboy is a 3/4 ton and they were only made until '77. It's worth noting because the frames are narrower on a highboy, 30" vs 34" iirc, so engine mounts that work on a highboy probably won't work on yours.I forgot to mention that the 78 is a Highboy short bed that originally had a 400 in it. Don't know if it makes a difference.
I was going to suggest running divorced on yours, but do you have enough rear drive shaft left on a short bed? Good luck - dentside IDIs are a great conversion, and if I'm not mistaken, someone on here has a dentside IDI 4 door Bronco conversion? I haven't seen his posts in a while, but I do remember salivating over that.
Diesel_brad
Dunce
i was going to say the same thing
lindstromjd
Black Sheep
Sorry about that, guys. I'm just going off of what the truck's owner told me. I guess it's just an F150 then. I'll just have to go back and look and see exactly what it really is though.
I'm fairly certain I won't have enough driveshaft left on the rear to run a divorced T-case. The truck is already lifted on the suspension as it sits now. Plus, the C6 that came out of the truck from behind the 400 was garbage, so it got torn down and I have the tail shaft and tail shaft housing sitting in my garage now. I didn't think it would be THAT hard to change tail shafts, but the more I look into it, the more I see differently.
lindstromjd
Black Sheep
Gotcha. Definitely just an F150 then.
I was thinking, if I cut the engine mounts out of the truck, and then bolt them up to the engine, and put the engine on my lift and sort of mock it up in the engine bay about 6" above the frame rails, could I just cut the mounts where they would sit with the 6.9 between the frame? I'll cut and drop the front cross member about 3", unless someone can tell me if I need more?
hairyboxnoogle
Full Access Member
I have a 7.3 /zf5 /np205 married under my 79 F350. (sig) I stuffed the motor as far back and down as i possibly could. I had a 2" body lift on it for the super cab swap and every bit is needed to clear the tranny in the tunnel. Really its pretty striaghtforward. Building motor mount towers is the biggest part making everything fit just right, then moving the tranny xmember back. Mine worked out to offsetting the holes, put the foreward holes of the xmember in the back holes on the frame, roughly 4". Contrary to above, i find i have lots of room between the fan and radiator. Enough to space the radiator back a few inches an stuff a 7.3 psd intercooler in there. I have little to no room between the firewall and the back of the engine, i had to flatten the pinch weld on the firewall. One thing to check on after all said and done is oil filter to front diff. clearance. without a lift, a remote oil filter will be necessary. Starter location can be really fun, but its doable. Wiring really isnt all that bad either. I ran most hots to the un-needed ignition power. But had to run a new hot to the GP controller. With the way the front frame crossmember is in the half tons compared to the 1 tons id say you would have a little more room to move the engine without the oil pan getting in the way of the xmember.
On the other hand, how youre going to make the half ton suspension carry an engine thats twice as heavy... thats all yours. The coils really arent going to like the extra 500+lbs. I dont think the D44 ball joints will enjoy it all that much either. And being a 1/2 tno i can assume you dont have the super cooler, which you may want to upgrade to. I improvised radiator hoses, maybe you can find some that will work without cutting, or use the diesel radiator. I know you have to notch the 150 frame to fit the super cooler.
On the other hand, how youre going to make the half ton suspension carry an engine thats twice as heavy... thats all yours. The coils really arent going to like the extra 500+lbs. I dont think the D44 ball joints will enjoy it all that much either. And being a 1/2 tno i can assume you dont have the super cooler, which you may want to upgrade to. I improvised radiator hoses, maybe you can find some that will work without cutting, or use the diesel radiator. I know you have to notch the 150 frame to fit the super cooler.
