The Stovebolt Site Forums The Shop Area The HiPo Shop AD: I6 to V8 Advice, Pointers Needed

In rebuilding my '51 3100, I'm going to be putting a 383 small block in place of the (not-original) 235. I know some of y'all have done this before, and I need your advice.

I'm going to order a set of "swap" cross members, mock up the position, and drill the mounting holes before having my frame sandblasted and powder coated. (I've got an old TH350 to use for setting the trans mount, but plan to install a 200-4r for the overdrive advantage.)

Whose crossmembers are easiest, and whose should I avoid?
What do you wish you'd known before you started the swap?
What's the best way to position the cross-members, to ensure the distributor clears the firewall AND the fan clears the radiator?
What about the height, to ensure things end up level? (The frame is on jackstands now, and I plan to replace the springs because the driver's side sags...)

Will a small block fit without modifying the inner fenders?
What about the steering box? (I plan to keep the original axle, steering, and column.)

I'd be grateful for anything you learned along the way that might make my swap simpler.

Thanks!!
mark.
'51 KY 3100
http://home.alltel.net/hd99fxst/pickuphome.html

MY ADVICE DON'T DO IT!!!!!! UPGRADE THE 235. WELL YOU DID ASK FOR ADVICE. ron

It's a lot of work. You'll need to reconfigure your steering, brakes, firewall and electrical to fit that V-8 in there. I did it to my 1 1/2 because the engine was locked up and I had a pile of used parts to build with. Good luck and be sure to ask specific questions if need be,
Scott

I have not done this swap, but I did see a GMC with A v8 and the original steering box and column.
the colum was cut, box moved back on the frame to clear exhaust. A bracket made to hold bottom end of column to the floor, and universal joints to reconnect the two again.

Steering interferance is probably the toughest part of this swap.

I think my solution to the problem would be to convert to power steering using one of the kits that move the steering box ahead of the axle.

It's not that hard a project. I installed my 327 back in'73 and am still driving it. The biggest problems were steering box clearance and tie rod clearance. I left the stock crossmember under the trans and under the bellhousing. The front mounts were made out of plate to box the frame rails with 2" square tube mounted at an angle from the frame to the motor mounts. The dist. clears the firewall with no modification and the fan clears the radiator by about 2". The rear end is a 12 bolt out of a c10. I did make a spacer to move the steering box out about 2", but that got changed to a toyota box with a Jeep Cherokee tilt wheel. The trans is an m21 4 speed. So far, it's held up great - towing a boat, hauling landscaping material and as a daily driver / only vehicle for a long time. The most fun is smoking ricers.

I'm hoping to keep the stock steering wheel and column.

nvrdone -- Would love some details on how to move the stock steering box out. Could you send me a picture of your spacer?

OldSub -- Is there a power steering conversion kit out there that would somehow adapt to my stock column? Maybe, cut it off and weld on a universal joint?

ron -- I didn't do it. At least, not in the FIRST twenty years of owning my truck. But now, it's time. I need a V8 under my foot.

Thanks!
mark.
'51 KY 3100

It'll clear the inner fenders. It'll also probably void your bowel if you don't upgrade to disc brakes and coil spring front end--i.e. a Mustang II or similar mod.

I know you didn't ask about that. But an AD with the stock front end spooks me quite enough thank you when it's chuffing along on the original motor, let alone careening around with a 383 like a hog with a firework up it butt.

Anyway, upgrading the brakes and suspension one way or another should be top of your list. Others here will chime in with various possible setups.

Just my 2c.

Good luck! Remember we'll want pictures!

BTW Peg or John or somebody---Why are the posting times correct but the editing times all wrong?

I drove my '49 with a stock 216, then with a built up 235 and finally with a 350 smallblock. The 350 version was the on I enjoyed the most.

\'49 with 350

The stock front axle has mid 70's Camaro/Nova disk brakes with a manual dual master cylinder from the same type car. I used a brake proportioning valve from a 1/2 ton Chev pickup, again from somewhere in the '70s. The last rear end I had in it was a '69 Chev Impala 12-bolt. The brakes worked great.

The steering box was moved out about 2" and the hole in the firewall just opened up to let the column move over. I couldn't detect any noticable change in the angle of the steering wheel and it drove just like it did before the swap.


I ran the stock radiator w/o heating problems (even in 105 degree weather running across the desert).

The upgrades made the truck a very dependable, useful and enjoyable ride.

OlBlue

We used a cross member we ordered from Chevy Duty when we swapped for a 305 we pulled from another truck. As I recall, we had to cut the cross member down to fit and have it welded, but that was 10+ years ago so I'm a little fuzzy on the details.

We are also using the stock radiator with zero problems after all these years. Like OlBlu, we're also running the stock front end, but I drive like a grandma on her way to Sunday church.

I did a 350/350 in a '51. Here is what I recall. The inner fenders are fine..lots of room. Fan to rad clearance is actually too much, not a point to worry about. If you start at the tranny mount with the engine and tranny together, the first critical measurment is to get the tranny near the floorboard, but not touching. Position it and make a temporary mount. Using jacks, adjust the engine to a level plane. This is a combination of forward enough to fit a distributor in without firewall issues, and level to the eye in the engine compartment. The V-8 will always look like it is sitting way too low but it isn't. Again, unless you "re-hump" the floorboard, initial height is determined by where the transmission meets the floor..everything else come from this.

My HEI just cleared the firewall..no chopping required. There should be no chopping on this swap, there is gobs of room.

I swapped and moved my steering box and installed a different column...the header to box fit can be a beast. Someone will tell you what headers to use that allow a stock box. The front to back measurement of the engine might be critical if trying to use a specific L/H header and stock steering box.

I never felt the brakes were an issue with a swap to a larger engine. If you go so darn fast with your new motor that you can't stop, maybe you deserve whatever happens to you.

Stuart

i used a motor mount kit and cross member from chassis engineering in my 49. mounts bolt in and crossmember bolts up to original location once rivits are drilled. it went fairly smooth although did have to move motor mounts 1/2 in forward than the measurements they gave in the directions.good clearance everywhere. although ther instructions say with stock steering the box needs moved out slightly. i have also used their pacer front end kit and just got done installing their bolt in rear end kit which is really a slick set up gave it a 5 in drop and a real clean look to the rear of the frame. i would definately use their products again......whid

We B Old, I understand your sentiments. I too have a '52 with a non-original 235 in it. I really don't like this engine. It is torquey right off of idle, but it's way too small an engine for a truck like this...it won't get out of its own way! I know, I know, back in 1952, this truck lived on a ranch in Wyoming and it was fine for that. But now it lives in Denver and barely keeps up with traffic.

I bought mine because I don't like the modern styles. I love how the 235 looks, but although the truck is set up for towing, it barely handles a car on a flatbed. I need more power.

I saw the Hot Rod magazine article on the I-6 build ups, making 300 hp. For a street truck used just for cruising, I'd do that in a heartbeat. In fact, I am seriously considering turbocharging my 235, just for a little more poop when I need it. But not even that will be enough for towing duty.

So I too am destined for a V8 swap. The turbo 235 project will hold me off for awhile, but eventually, I'll end up hotrodding my truck. I'm collecting parts for a 406, someday with a roots blower on top.

You other guys, I agree the stock suspension leaves a lot to be desired, but I like my truck riding like a truck, way up in the air. I really don't want to drop my suspension. Hasn't anybody else ever grafted a modern truck suspension on a stovebolt, rather than modified car suspensions?

I too am looking to put in a 305 V8 and 700R4 from my '91 camaro donor car. I like the looks of a stock truck the best even though my son wants to lower the truck some. Does any body have pictures of this swap? There uses to be an article on the net but I can not find it anymore. Have a great day and enjoy your truck, Wayne

Believe it or not, this truck has a 350 4 bbl. engine in it. It didn't change it's ride height any either,
Scott

Cut the column, put a bushing in the end of the tube, and use a universal and shaft to extend to the new steering box. Several venders offer a kit to mount a box ahead of the axle. I've seen a bushing offered for sale, but don't recall which one.