All Small Six 170 rods in a 200 ?

[65EPup200]

Firstly we are in the U.K so it makes it a bit more difficult to work with these engines.
We purchased a 200 and C4 for our 65 Pup, engine looked great, painted, chrome bolts, new water pump, six branch & Clifford Weber carb conversion.
Bonus it was a 78 so had the big valves and hard seats.
Looked a steal!
We took the head off to check what we got.
Bores with a ridge you could fall off !!
“Don’t judge a book by its cover “
Anyway decided on a rebuild, bored 60 thou, decked the block to zero, new small bowl pistons & rings, ported the head & cc’d, three angle valve job.
Comp cam & kit , skimmed the head to get 9.8 to 1 comp.
Now the 200 rods are a miss match, question is are we pushing our luck using the 170 rods, cleaned ,balanced and ARP bolts ? or source new 200 rods ?
170 rod fit but the 200 has a stouter beam.
Street use not high revs.

 

[drag-200stang]

Here in the US the 170 and 200 rods are the same until sometime in the about mid 70s the 170 was dropped and the 200 changed to cast steel instead of forged, and later back to forged. The cast rods are bigger and heavier.
Not sure what you have there.
If your engine is like the US maybe you have 200 cast rods and forged rods. Does the 170 rods have C3 on the side of the rod. Can you post pics of the rods. The 200 cast rod is stronger but heavier than the forged but the 170/200 forged rod is less prone to breaking it will bend first but not break.

 

[65EPup200]

Here in the US the 170 and 200 rods are the same until sometime in the about mid 70s the 170 was dropped and the 200 changed to cast steel instead of forged, and later back to forged. The cast rods are bigger and heavier.
Not sure what you have there.
If your engine is like the US maybe you have 200 cast rods and forged rods. Does the 170 rods have C3 on the side of the rod. Can you post pics of the rods. The 200 cast rod is stronger but heavier than the forged but the 170/200 forged rod is less prone to breaking it will bend first but not break.

Thanks for the info, Yes we have the forged steel 170 rods. I think we’ll use those rather than mess with the miss matched 200 cast rods.