3406b truck engine Up grades

[rmllarue91]

Hi hef My 4mg 3406b 300hp is wore out.
I'm looking for arrangement to rebuild as 425hp and possibly kit numbers.
I know I need turbo, piston packs, injectors. For pump going to need camshaft and unit pumps. I'm doing out of frame ground up as they say. block head rods and crank going to machine shop. I read the early 7fb was best for making power but I'd think any 425 arrangement will do. It's in a single axle service truck and it's not to shabby at 300hp thanks

 

[Tyler d4c]

Does your truck have a air to air on it.

 

[Junkyard]

I had a 7fb in my 359, it was 400 from the factory. A little tweaking the pump and it would walk the dog. I’ve got the data tag at the shop, I’ll post it next time I’m there.

 

[colson04]

I had a 7fb in my 359, it was 400 from the factory. A little tweaking the pump and it would walk the dog. I’ve got the data tag at the shop, I’ll post it next time I’m there.

Cleaning out my old shop office to make it a bathroom I found this. Kinda choked me up lol
View attachment 188666

You shared it before in the memories for us old truckers thread. I saw your post and remembered seeing it before. Search function found it.

 

[Truck Shop]

A 4MG should be CAC-charge air cooler. The 4MG came out in 1986 first series of air to air. Waiting on a call back from a friend that has all cat AR numbers on file. If you want it.

 

[Junkyard]

I knew I had posted that here, didn’t take the time to look. Thanks for digging it up!


I had an 86 359 425 Air to Air as well. Might be able to get that full S/N as well from my files.

 

[rmllarue91]

Does your truck have a air to air on it.

Yes has air to air

 

[Tyler d4c]

Yes has air to air

Thats a good start in my book

 

[Truck Shop]

The 4MG 425 hp that you want uses a performance spec #OT7799. But for total parts comparison I need the
performance spec off your 4MG 300. Because there were more than just one 300 spec's. Once I have that I can
tell you which pistons, turbo, nozzles pump torque spring and all other parts needed to build a true 4MG 425.
Going just off the AR# doesn't get it. It will also be information for the pump work that needs to be done.
The performance spec should be on the engine tag and start with OT.