The Stovebolt Site Forums The Shop Area The HiPo Shop 73 - 87 IFS info

Over the last few weeks I've had several inquiries on my IFS swap. I've finished the swap and posted some updated photos on my webshots account. Many people don't consider this a viable swap because of the width. After having the crosmember narrowed, it all came together pretty good. As you can see, the wheels fit nicely in the wheel well. Those are 16 x 7 torq thrust II's with four inch back spacing. The tires are some junk 225 60 16's that I have on there to move it around. I plan on using a 215 70 16. I'm running 17 x 8's out back but haven't decided on what size tire to use. 3" drop coils are installed but I also will probably add 2" drop spindles to lower it a bit more. If you are considering this swap it really is not as bad as some think. The junk yards are full of 73-87 half tons and the cost of the suspension is relatively cheap. I'm pleased thus far with my results.

Mobile I'm interested in how you narrowed that crossmember. The mounting to the frame appears to line up real well. I'm wondering if the two cuts were parallel or if you pie cut it to make the crossmember hit the frame square.

I really can't say for sure. I dropped it off at a shop and told them to narrow it by 1.5". I'd be more inclined to say that they were parallel because I had to grind alittle to get it to mount to the frame. After looking at everything again, I believe it could have been narrowed even more by moving the saddles.

Looks good to me. Main thing here is that you are satisfied.

What is the overall width on the front wheel/tire from outside to outside ?

I am curious because I am working on the same swap on my 48 3600. I just finished boring out the center holes on a set of 2007 Jeep wheels. They are 17 x 7.5", 5 lug on 5.0" bolt circle and have a 45mm (about 2") positive offset or about 5.75" backspace. I narrowed the 78 crossmember 1.5" for a perfect fit with the 3600 frame (this one is narrower than the 3100 frame). That said, this combination gave me about 68.5" from outside of tire to outside of tire. I am using a 235/65/17 tires front and back. I do not have all of the parts for my front end sheet metal yet and would like to know if this is going to fit within the stock front fenders ?

Mobileortho - your truck is looking good.

Oldsub - I narrowed the crossmember by using 1.5" wide masking tape around the center and cutting along either side of the tape with a sawzall. No angle cut was necessary. With some trimming, I welded the cut off piece inside one of the sides using several plug welds. I then used this as a guide to mate the two halves back together. The assembly was bolted to the frame and then welded back together for a perfect fit.

Nice! Great thinking outside the box. Do you think it would be feasable to shorten the control arms upper and lower equal amounts? like say an inch?

49chevyman- I'll try yo get you those measurements this afternoon.

Unsafe6 - I had the control arm shortened too.

mobileortho,
Man... It really looks nice ! Great Job !

Thanks Tab!

By control arm do you mean the tie rod?

Oooops! I meant the center link!
Chevyman, I'll get those measurements Thur. I forgot about my daughter's band concert tonight. I have Church tomorrow.

Mobileortho, no problem, get them when you can. Yours looked like the tires were tucked perfectly, just enough room that the will be no fender or frame interference, and the fender opening is filled about right. Too many MII installs bury the wheel too deep for my taste.

One other question for you while I am at it. No sense in me re-inventing the wheel with you already forging the way. I noticed you have a rag joint on your PS box. My box is mounted in the same place, but I assumed due to the angles involved, I would have to put a u-joint on it and the bottom of the steering column to make it work. The intermediate shaft also looks like it is going to have to go through the inner fender. Mine are not installed as I said before, but I was wondering if you had already mocked the steering up and solved some of these problems?

Unsafe6 - a couple of companies make shortened or narrowed control arms for the 73-87 Chevy truck that could be used with this swap, but they are expensive. Instead of doing that I would just use a MII set-up, unless you are trying to stay cheap, but factory looking like me.

mobileortho
If you have time bring your tools on over here!

I need to take more photos. The pic's with the rag joint mounted were taken last year as I was mocking things up. The final assembley has two u-joints, one attached to the PS box, the other to the column. The steering shaft will have to pass through the finder well.

Looked through my Webshots again and came across this shot showing the joints.

Thanks, that is about what I figure mine is going to look like.

How about the front tire measurement ?

Roughly 71"

Thanks Mobilortho !

Chevyman, depending on how you mount your engine, you may have to use a floor shifter if you plan on using a automatic tranny. The way my engine sits I cannot use a column shift because the lower shift lever hits the back of the engine. I'm thinking about a truck Megashifter or a Lokar unit. I like the Lokar but they are pricey if you get the shifter, boot, indicater & sending unit. The Megashifter will be about half the cost.

I am using a 292 six cylinder. It is the only thing that is rebuilt and ready to go. I have mocked up the S10 tilt column with column shifter and it looks like it will clear everything fine.

I used a Lokar shifter in my 49 Chevy car (350 w/ 350 auto). It works well.

Thought you were installing a V8. The 292 should clear easily. Is that a stock engine?

It is almost stock. It has been bored 0.040 over and has a mild cam. I may put a different intake and Fenton headers on it, just for a nostalgic look.

I did actually have cut into the firewall to recess the engine some more to get enough clearance for a cooling fan between the front of the engine and radiator. I thought it would drop right in, but that was not the case.

So when do we get to see some pictures?

I am working on setting up a Webshots account. I will post some soon.

Here are some pictures.

http://community.webshots.com/album/563392579KNgIaO?vhost=community

both trucks look good! the front track width looks fine and you really don't want real wide tires on the front anyway!

Looking good. What rear end are you going to use?

I am going to use the free 78 truck rear end. It is a 12 bolt, 3:08 ratio. I am going to wait until I drive it to see if I will have to change the gear ratio, but I suspect I will have to put in a 3:43 or 3:73.

How did you like my $100 bed ? Picked it up at the Charlotte Auto Fair a few weeks ago.

I have the frame welded back together. Now I am working on making the dropped front end work. The drop spindles and 16" wheels with over 5" of backspacing are not working well together. The lower control arms are having to be severely trimmed.

When you say control arm are you referring to the center linkage? If so I had mine shortened when the cross member was shortened. I have some drop spindles on the way. It should work out well. Oh yeah, the bed looks great!

Kevin:
You need to edit your profile to add your Webshots to your signature.

was the TPI a bolt on or did you have to do some machine work?

It was all bolt on. The only modification I had to do was have an extra accessory hole drilled into the head for the serpentine brackets.

Mobileortho - I mean the control arms. I also had to take 1.5" out of the steering center link when I narrowed the front crossmember. Mine looks just like yours. I have studied your photos to learn what I could before I started modifying mine. I will take some photos once I get all the bugs worked out of them.

I am trying to get the front crossmember about 7.5" from the floor. That will set me level with the flipped rear end. I have 3" dropped Belltech spindles and have cut 1.5 coils from the stock springs and I am still not low enough. I may have to install airbags on the front, but I hate to add the complexity of the compressor and controls.

The interference problem with dropped spindles on the 73-87 trucks is a common problem, especially with smaller than 17" wheels with more than 3" of backspace. Check out the 73-87 truck forum suspension:
http://forum.73-87chevytrucks.com/smforum/index.php

Big Chevy,

I edited my profile to add the link to my Webshots album. But I cannot change the text that is shown in the link to "53 Chevy Truck", it just shows the whole url instead. How do I change it ?

I'm suprised that you are having the problems with the ride height. Is the engine already installed? That will bring it down some. I have a set of dropped coils right now but the spindles should be here next week. I thought about leaving it as is but decided to use the dropped spindles to eliminate the space between the wheel & fender.

I went to the link you provided and say the issues with brake lines & dropped spindles. Is that the same problem you're having?

I have no brake lines installed as of yet, but I will route them so that there is no interference problems.

The engine and 700R4 are installed. I even hung all the front end sheet metal and dropped the hood on it to see how it was going to look.

I am going to buy a pair of 3" dropped coil springs because I know the stock ones I have cut will be too stiff. If that does not work I guess I will install air bags.

Let me know how the spindles fit. What brand did you buy, and what height drop ?

I bought them from someone on Ebay, not sure of the name brand. They are 2" drop.

what did the TPI system come out of?

'87 Camaro converted to speed density.

I was reading my Classic Trucks magazine last night and came across an ad for a bolt in crossmember and a-arms that would narrow the track width of a 196? - 1987 front end by 2". This seems like a viable option for those that want to use this front end and not have the wheels stick out of the fenders. It would also prevent having to cut a chunk of steel out of the middle of the crossmember and other components to narrow the track width.