Guys,
I would like to swap the current 305 TPI in my 87 TA to a 350. I can get a 350 crank for $75 dollars and all I'de need for the crank is new bearings because it's ground down 10 under.
First off, will I need new rods or are they both 5.7 or???
What all else is needed to swap to a 350 from the original 305?
Thanks alot,
Donnie

 

Doesn't the 5.0 and 5.7 have the same stroke?

 

Yes both the 305 and the 350 have the same stroke 3.48 and the same rods 5.70.

 

305 and 350 cranks are the same stroke, and even the same castings. The only difference from the factory is the balancing, since the pistons are slightly different weights. Rod length is the same. The only thing that is different between the 2 motors is the bore.

So, if you put a 350 crank in a 305 block, you come up with {drum roll, please.......} a 305. To make a 350 you have to start out with a 4" bore block, which cannot be done with a 305 block; their bore is 3.736".

 

The 5.0L and 5.7L both have a 3.48 " stroke. Do not waiste your time with putting the same stroke crank into the block (i.e. the cranks are the same). Both the 350 and 305 use a 5.7 rod. Look for a crank with a 3.75 stroke (400 crank) and you can reach ~334 to 340 cubic inches if you bore .030-.060 over. But if you put in a 400 crank, I think that you need 400 rods (5.565") due to clearence, but I am not sure. You can not get 350 cubes from a 305 block, the difference is in the bores. the 350 starts with a 4.00 inch bore and the 305 starts with a 3.736 bore. There just is no room to bore a 305 to 4.00".

 

I have a 400 crank,flexplate and harmonic balancer I'll sell you for $100.00 + shipping