1971 f100 4.6 Mark viii CV-IFS FN-10/MN-12 IRS

[yarko]

How's this project coming along?? I'm thinking of doing the same set up.

[redlinemotorsportts]

Yep, progress, but really spread apart. i want to take some picutres of everything soon, on break from school for a few weeks.

[redlinemotorsportts]

So long overdue update, but here it is.

Ordered stock 2003+ vic motor and tranny mount kit, plopped the engine in place.



Dropped the ball on pics because junk was so spread out. Really on and off work. So about early july we completely stripped the irs apart, and me and the old man put new carrier bearings on, 4.10s from that explorer on, set preload and got the gear paint just right all in the aluminum mark 8 pumpkin. We used ford racing trak loc clutches and s spring that was donated, and all put in the thunderbird trak lock carrier.


2.73 from tbird diff pinon vs 4.10 explorer pinion.


Around mid july i scored on a craigslist bed after months and months of hunting, a 8' camper special box for $150. Got him to throw in the valance behind the bumper too.


Didnt ever get a good picture but me and the ol man were talking about how irs was mounted up about late july and i tossed the idea out that the front mounts look like and kinda ugly. Thought it would be cool to bring them up and tucked away sort of, not super serious about the idea. Well, he went ahead and chopped them up, so we plated them all the way around. maybe bright them up 3" or so, no official measurement. The stock rubber mn-12 mounts were junk and one was missing and nobody sells them. We decided to buy universal rubber body mounts, takes a 1/2" bolt. We hole sawed 4 1/4" disks out and i welded them on top and bottom into place. rubber mount goes under in the pocket and one on top. Can kind of see in the picture. Threw it all together with mark 8 lower control arms and new rebuild housing.


So fast forward about a month to early august maybe. one of the surrounding salvage yards posted a 68 f250 that showed up, so we bombed down there to molest some cheap parts. I got a almost perfect hood, entire front grill/ light assembly, steering wheel, radio bezel, inner fender firewall connector deals, and bumper for $150 total. Stoke of luck, as saying my original hood was unexpectedly more junk than i thought.






Alright, so i started at a state college for HD truck and diesel, so time has been scarce. Good time for me to plan out the next 5 steps though, learning more of new stuff to do and ways to get it done faster. So work here and there, but i got 5 weeks of winter break (coming to a end currently) But we got going on mounting the IRS up finally.

Got to play with the new toy.


Mockin up to see how our plates are going to look in the rear.


Fabbed up a little cart to shuffle the irs in and out under the frame rails.


Designed and torched out 1/4" rear mounts.


Measuring the axle centerline via 67-72 ford measuring book, we found out where the plates would a land and leveled the frame, and level cut the notch.


Tacked in the plates and 33.5" 2x2" 1/4" crossmember. Drilled the coil buckets out for a 1/2" bolt to hold em up top.



So we didnt know what to do about pinion angle, and ive heard 2 degrees on tailshaft and at the pumpkin is perfect. So before we made front irs mounts we pulled the engine and removed the two crossmember the trans has been resting on, way to high up crossmembers. Will be replacing them both, dont yall worry.



With the engine and cab back in place, what we learned is you CAN set pinion angle at 0 degrees to the frame, if you are making a new trans crossmember. out mark 8 driveshaft is to long even though it fits (juuuuust barley) We had to lower the trans, jam the driveshaft over the pinion nut, and jack the trans back up. You can determine all your driveshaft angle just by messing with the tailshaft angle.


With that all squared away, i torched out the 4x4 and plate i need, drilling the bolt hole for the lower mount.


Better shot of the irs mods, 1/4" thick disk welded on with universal mount.


Tacked them up, dropped the irs and burned them all in. Not to bad for self taught i guess! Going to be making plates to cover the holes so sh*t dont get in. Thinking drill and tap and use 2 bolts to hold the plates on.



Bought sohc 4.6 long tube pace setter headers ment for a stang off cl for $75 too to experiment with because i havnt seen anyone do long tubes on a swapped 4v yet. Flanges need to be cut off and dohc oval port plates welded on. Pics were before crossmember was removed, but with them mocked up now, it just looks like the drivers top frame rail needs a slight notch and passenger motor mount grinded down, overall fit is better than i thought, super tight as always. Bought used SLP LM2 mufflers from a mustang page too for $100. Planning on a x pipe or mac prochamber.


Fits perfect!


Thats all for now folks, def rolling on this project now.

[redlinemotorsportts]

More pics, college break is over. Should be a roller with a drill of the hubs!

Template and ticky taky



Frame plated





Coulda built it higher if it was farther back now that i look at it but came out good for my first one at least


Better pics of headers stuffed in

[redlinemotorsportts]

Got most of the body mount bolts and spacers kinda together, and picked up a 77-79 core support. Replaced a rusted cab frame mount with some plate steel, pic shows how rotted it was. other side fine.



Bolted the cab mounts on up front and just set the cab on to get the pans off the frame. Bolted the core support on and a fender on. Tire is like 28.25" od ish, on a 17. Looking to run maybe a 29 od tire abouts with a 20" and wide as possible.



Looks like i got some room for a slightly wider rim. 2" maybe


Hubs got drilled by Stu at http://www.irsmachining.com/ with very good quality. Sent the hubs and lugs to him, he drilled them and pressed the lugs in and couldnt be happier.


Got the correct dohc header flaunges, they are 3/8, slightly thicker than stock flaunge. Should be fun welding those on. CNC plasma cut with good quality, looks like holes need a bit ran through but thats to be expected. http://www.ebay.com/itm/Ford-4-6-5-4-Mo ... cf&vxp=mtr


Dad puled through with a on sale Harbor freight 20 ton press (ballin on a budget) and he put the bearings in the knuckles then the hubs in there. Bolted the other roller tires on and rolled it outside to clean under this pig and get some shots. Pretty happy, been 1 year 5 months since its rolled.







Looks pretty good. Things im thinking of doing next:
form and weld cab mounts on to floor pans
patch small holes in front fenders
buy complete rear brakes and e brake cables, make braket for it.
cut 8' bed down at some point. should be straight forward ish
find passenger inner fender/make custom inner fenders
get mark 8 radiator and fans
wire engine
brakes in there somewhere with fuel system ect.

[redlinemotorsportts]

Little bit of a update, nothing to much but getting progress done. This is all about the headers, i cut the flanges off and adapted the new dohc flanges on. pretty much sawzawed the old ones off, squashed, relief cut, and used hammers/plyers/vice grips and expanded them out till they fit into the new flanges. I then tacked them, made sure they still clear everything, used a punch and hammer to expand the pipe in the oval port as much as i can and welded it in. There were some gaps i had to fill where i couldnt get it to expand as much as id like to, but i got a carbide bit and smoothed it all out. it came out way better than i thought really. But i would really, really not do this again if i could prevent it .

I did modify two primary tubes to clear the new steering u joints/shaft. A lot of cutting, fitting, tacking, trimming ect. But did come out good. I really wish i had a tig welder for all of this but i make it look good with the ol hobart mig. Was able to use all the bends from the old header pipes to make it work plus a little section of straight tube.









Working on the fenders now, need patching. Next is to finish those up and start on the box.

[yarko]

ive loved following this build. any more updates?

[redlinemotorsportts]

ive loved following this build. any more updates?

Yes and no. moved the thread to fordtrucks.com http://www.ford-trucks.com/forums/14392 ... v-irs.html

Def have stuff to post, but im just trying to find a good time to post it all.

[hfdco4]

Keep it alive here as well. This is still a good forum as long as we keep it alive.

[yarko]

Is there a place on line to find the patterns for the mark viii irs mounts? I know there's kits you can buy but at $300-400 it seems a bit steep. Id really appreciate any info you can give me. Thanks alot and keep up the great work!

[yarko]

This is one of my favourite build threads.... Any updates?