1970 318 to 426 Hemi swap. What's needed?

[STXCuda]

Like the title simply states I got a 1970 Barracuda 318/904 I will be doing a 426/727 swap. What is needed to make it bolt on? I know K-frames are different. Is there a mount/bracket kit to make the swap and I will be using the original style shaker so proper height and positioning will be needed. Thanks for any help

 

[tonysrt]

Hemi uses deeper pan and K frame of hemi has a piece welded to the bottom to protect the pan. I used a Hemi K frame that has that piece on it already and use regular hemi motor mounts. I also used the poly insert motor mounts for the strength over the rubber mounts. That piece is available and can be welded on k frame, also 440 6pack motors had same piece to protect pan.

 

[70chall440]

You are going to need conversion motor mounts, a E body hemi K frame or have your K frame converted (assuming you are using a 426 that uses the original mounting configuration, there are some like the Mopar Performance blocks that had the same mounting ears as a 440). There is a guy floating around FBBO that converts your K frame and once converted its like stock.

You will need to change your torsion bars if you want any kind of decent ride and the car to handle at all. You should add at least torque boxes on all 4 corners but I would also add sub frame connectors. You might want to upgrade the leaf springs and perhaps the rearend as well (many people have used an 8 3/4 behind a 426 so don't let the hype scare you unless you are making big power). You should upgrade the fuel lines to at least 3/8", and you will probably want a new driveshaft with larger U joints.

Obviously the hemi will require unique exhaust which can be a challenge to some but other than that it isn't that big of a deal. Despite the 426 being "unique" its just an engine at the end of the day (albeit a very large one).

Look it isn't rocket science and many people have done it, some better than others. Think it through, make a good plan and execute it.

 

[Chryco Psycho]

I would not waste you time with conversion mounts & the original K frame , you can get proper K frames using original Hemi mounts , the conversion mounts really don't work well overall .

 

[70chall440]

I would not waste you time with conversion mounts & the original K frame , you can get proper K frames using original Hemi mounts , the conversion mounts really don't work well overall .

Not doubting you but I am interested in why you say this. I am getting ready to install 2 hemi's into 2 70 RR's and the plan is to use the Tin Man conversion mounts on one of them.

 

[Chryco Psycho]

I did this for a customer a while back using a 440 K frame & conversion mounts , yes it works But almost impossible to get a dipstick to work , the engine was not truly correctly positioned causing other issues & may be really bad with a shaker , we did a vanishing point chall with the ralley hood .

 

[70chall440]

Appreciate the information, I am going to be doing an install of a 572 into a 70 RR but we cannot modify the K frame because the car is going overseas and they have laws prohibiting it.

 

[Chryco Psycho]

You should be abl to install a different K frame properly set up for the Hemi .

 

[erickson]

I reproduce Hemi K members I have 1 with the steel motor mounts $600.

 

[70chall440]

You should be abl to install a different K frame properly set up for the Hemi .

I do not believe the client is interested in a different/modified K member. Should something happen to the Hemi down the road and he wants to go back to a wedge it will be an issue. That said, Hemis have been put into a lot of things over the years and I suspect most of them did not have a "hemi K frame". Not saying there aren't or weren't issues/compromises but obviously it can be done.

Just to be clear, I appreciate your advice and under other circumstances would agree, but in this instance I think I am going to be using conversion mounts. That said, I am also putting a 426 Hemi into my own 70 RR, in this application I am most likely going to use a motor plate bc the car is pretty modified (tilt front end) and I think the motor plate fits the build.

 

[70chall440]

I reproduce Hemi K members I have 1 with the steel motor mounts $600.

Ever thought about making/selling a kit to do this? I believe I have seen some pictures of your work and it looks awesome but shipping the K member out is a PIA. I think you would have some interest in a DIY kit.

 

[Ele115]

The opening in your core support will probably not be big enough for the 426 radiator. The 318 radiator isn't going to cut it.

 

[70chall440]

The opening in your core support will probably not be big enough for the 426 radiator. The 318 radiator isn't going to cut it.

Someone (eBay?) sells a replacement panel for the right side of the core support to make it a 26" opening. I did this on my Cuda while I had it apart, have to drill out some spot welds and then weld it is. You can also just cut the opening but you will need spacers for the right side of the radiator bc the core support has raised parts which the radiator bolts to so if you don't space it out the radiator will sit crocked.

 

[erickson]

We don’t do kits The reason is we did sell a few nobody got them welded in correctly And then they complain about it all of ours done welding fixture

 

[Ele115]

I would just about predict that one like it came from a crystal ball!

"My engine just fell out! Your product is junk dude"

Have no fear, my neighbor welded it

 

[70chall440]

We don’t do kits The reason is we did sell a few nobody got them welded in correctly And then they complain about it all of ours done welding fixture

Gotcha

 

[tonysrt]

1 other thing I had to change going from a 440 to the 472 hemi was the starter cable. Seems like the older cable, 440, didn't reach around the bigger heads and the bracket at the back of the drivers head to hold the cable. It ain't cheap that battery cable. When I had the K frame in and thought I was already to go, but every step thereafter required another call to year one to get another hemi only part. But 20 years later still running great.

 

[shakerjoe]

1 other thing I had to change going from a 440 to the 472 hemi was the starter cable. Seems like the older cable, 440, didn't reach around the bigger heads and the bracket at the back of the drivers head to hold the cable. It ain't cheap that battery cable. When I had the K frame in and thought I was already to go, but every step thereafter required another call to year one to get another hemi only part. But 20 years later still running great.

Mention hemi…cheap goes out the window…

 

[Ronbo73]

Have you thought of a company called Schumacher creative industries. They have been around since 1992. They specialize in engine swaps. I've never used them.

 

[erickson]

They have been shut down for two years supposedly someone has bought them