'73 318 to 400 engine swap

[Nacho-RT74]

Nacho, so the wiring harness won't swap either ? This is also news to me, as I was lead to believe that it would.

Will need to enlarge some wires, like the coil and distribuitor... Remember BB got this pieces in front of engine.

 

[YY1]

...if you can find a E body 8 3/4 with the springs still attached, that's a win-win to get rid of the whole ISO setup.

I think every E body got an 8 3/4 no mater the engine, and none were ISO.

 

[Bruzilla]

I used the Schumacher mounts and they work just fine. And no... you don't have to cut anything on the left side. I did have to modify the physical appearance of the driver's side header with a hammer to get clearance for the steering.

 

[Bruzilla]

I've been searching craigslist in like a 300 mile radius of me, (near Wichita,ks) and can't seem to hardly find complete 8 3/4 at all.

Found some for trucks, or bare housings, etc. but finding a complete one has proven difficult.

I hodgepodged the one on my 74. I got a 2.76 E body rear from YY. I then got a 73 Town & Country parts car with a 3.23 rear. I cut the mounts off the E body rear and had new ones mounted for install on a 71-74 B body. The E body rear is a bit narrower, but you can't tell visually. I swapped the center from the wagon into it, and also swapped the heavy duty brakes as well.

 

[YY1]

That's the way to do it.

You didn't cut the inner fender at all?

You didn't cut the driver's side K frame engine bracket like Schumacher says to do?

 

[vegiguy]

I did this swap on my '73 RR and am still struggling with it. Right now I'm thinking the BB radiator support is different because the replacement radiator I got has the flanges an inch or so further out. I may make a post about this.

I used the Schumacher adapter mounts and they DO call for you to cut the left side K-frame mount and drill new holes for the thru bolt. I agree finding a regular BB K-frame of the appropriate year would have bee much better (but much harder to get) because this all seems cobbled together now. Make sure to replace or put some finish on the bolts Shumacher gives you because they rust terribly over time and look awful then!

I also kept the original 8 1/4 rear end but installed an original sure grip diff. in it I found on eBay. The transmission yoke needs to be changed if you upgrade this to a 727 or A-833 (as I did). I didn't do anything to upgrade the suspension because the toque rods seem like they will handle the extra weight just fine. Increasing the diameter of them would have just made the car ride harsher.

This is a very difficult swap because of the parts required and how hard it is to find them. I wish I would have just went with a larger small block because it has been one problem after the other making this work (and I still don't have it ready to run). The car would probably handle better, too, with less weight in front. This swap was a mistake IMO.

 

[Bb70charger500]

Are you still needing help on the K frame matter I have 2 73 chargers sitting here one big block one small block so I can take pictures and mesurments if needed also the big block K frame is for sale shipping might kill you though I'm in south FL.

 

[vegiguy]

Are you still needing help on the K frame matter I have 2 73 chargers sitting here one big block one small block so I can take pictures and mesurments if needed also the big block K frame is for sale shipping might kill you though I'm in south FL.

I converted my small block 26" radiator support to a big block 28" support by cutting off the extra offset flange stamped into the left side (driver's side in the US) of the radiator opening using this picture of a 28" radiator support (courtesy of 69 Charger) as a guide of how it should look:

It's from my post on this issue (http://www.forbbodiesonly.com/moparforum/threads/need-some-dimensions-please.116504/#post-910501897 ). The right side holes look like the same on the 26 or 28" supports however I'm having trouble locating the left side holes which aren't there on the newly created mounting surface (the replacement radiator I have doesn't seem to have the mounting holes in quite the right place - although they are close - so this isn't helping matters). Any close-up pictures of the 28" radiator support and measurements would be helpful to me any probably any one else doing this swap since the 28" radiator is apparently the most common big block radiator (it's the only one available aftermarket).

 

[Bb70charger500]

I'll see if mine has that size opening

 

[Bruzilla]

That's the way to do it.

You didn't cut the inner fender at all?

You didn't cut the driver's side K frame engine bracket like Schumacher says to do?

No cuts to either inner fender, and yes, you do have to make the changes to the driver's side K frame tower as per the instructions, but that is an easy process. Just me sure to measure twice and cut once.

One other thing I did was go to Ace Hardware and buy some bolts that were 1/2" longer than the ones Schumacher provides. Made them a little easier to get in.

 

[YY1]

How's the plug access on the pass side?

 

[Bruzilla]

How's the plug access on the pass side?

Fantastic! And that makes up for the Hell on the driver's side. I can get 1 and 3 in from the top no problem, but 5 and 7 require getting under the car, holding my breath, cursing a lot, etc. But, that's with headers. I'm guessing a stock exhaust manifold would be easier.

 

[vegiguy]

With stock "high performance" exhaust manifolds access to the plugs on the drivers side is okay, but passenger side assess is a little snug but not impossible. All plugs are pretty much hidden by these manifolds when trying to access them from above so you have to feel your ways around to remove or install them.

 

[vegiguy]

I still say this swap isn't worth the trouble. Going to a 440 or 426 hemi might be, though, if the goal is to get significantly more power without being concerned with how the car handles. If not, going to a larger small block engine makes more sense because it's easier and cheaper. You could probably build a 340 or 360 up to get almost as much power as you could out of a 400, but the real advantage would be in having a car with less nose weight ( a good 70 lbs. less) so it would feel faster and handle better with the small block. Also you could access the spark plugs a lot easier!

 

[drobertson]

Deals are out there. I got a 440/727 for 150 bucks, and a 72 b body 8 3/4 for 50 bucks. Just keep on looking. It's really a pretty simple swap, imo, although I haven't done it, I understand what needs done. If your car is an automatic, you'll need a completely different trans, wheras a stick can just interchange the bellhousing. Shumacher swap mounts, big block engine wiring harness, and a water pump housing and radiator correct for a 73+ car, and proper brackets for all the accessories.