ive been having issues with the 400 in my truck, and im starting to thnk it might be something serious that will require a re build. i figured this would be a good excuse to do a swap. i found a guy selling a running 429 with a factory 4 barrel intake out of a school bus, not sure what year, for $400. anyone have some good or bad input?

 

Medium duty 429s differ from car/pickup 429/460 motors. Crank snout might be bigger, accessory drives different, bell and pilot hole in crank different. Not 100% sure on this, but when this comes up in the large truck forums where folks want to swap a 460 in where their 429 was, it turns out to be more trouble than it's worth.

Having said that, you aren't swapping from a 460, but this will be about the same as swapping a 400 to a 460, including a 100 lb + weight penalty. Figure a bigger radiator as well, along with exhaust, and all the other little things.

You will have to deal with the trans issue also--what trans do you have?

$400 won't go far on a rebuild of your 400, but it you end up spending another $400 on little and not so little items, maybe......

PLUS what condition is that 429 in? Have you heard it run?

You would end up with a bit more power than the 400, but not by much.

 

i currently have a C6 trans in the truck. he said it runs, i was planning to go and check it out in person. so it would it be easier for me to find a 429/460 out of a pickup?

 

Easy to hard:

--rebuild or repair 400

--swap in reman or good used 400

--swap in 460 from a similar truck, using all parts from the donor.

--swap in that 429 and "adapt" it to work with parts from an OEM 460 truck.

 

in that case, ill just stick with the 400.

 

Lots of threads here on the 400.

Minimum: Fix whatever is wrong. Add a mild cam.

If you need a rebuild with new pistons, you can add compression and a cam, and build to whatever power level you want.

 

true. i need this truck as its my DD during the winter months, so if it needs a re build ill ust go to the junkyard and buy a different motor to build on the side. but if im gonna do that, i may as well go with a big block.