Visit The Dirt Forum for More Information

Author Topic:   connecting rods
racer s
posted July 07, 2004 03:13 PM
will 305 and 350 rods interchange? Will it be worth the time and effort to take them out of a 305 (they are x rods)

posted July 07, 2004 03:40 PM
They are the same but will need to be balanced for your combo.

posted July 08, 2004 12:18 PM
Most 305's were NOT the same rod as 350s.

Most 305 rods had a heavy big end (around the bearing) with flat machined sides by the bolts. The also have a weak 1/2" beam. Some of the big ends had 'X''s on them making people believe they were the good rods.

350's had 2 rods.

The typical rod had a 9/16" beam and a lighter weight big end. Easily identified by the small machined mark by the parting line (just big enough to punch a number on).

The Pink rod, or true 'X' rod, had the heavy big end AND the 9/16" beam.

In my opinion, and the experiences we had at the shop, the typical 350 rod (with the lighter big end) recon'd with ARP or Pioneer performance bolts was the best solution. The 'X' rods were heavier, but proved to only be that.. heavier. Rod bearings usually fail from weak bolts or ridiculous over revs. Very rarely from the strength of the rod material itself. We had one 406 running this rod with Pioneer Perf. bolts (Years back there were occasional shortages of ARP bolts) for 3 years at 7200 rpm. After all those races the rods were still within .0003" of being perfectly round.

posted July 20, 2004 10:23 PM
I was just reading this and thought those 305 rods sound familiar. I went out and looked and they are in the motor I am getting ready to use. I got it from a friend that had it bored, new crank and pistons. Its a 355 and same as I have been running. Just stock bottom end parts. No balancing has been done on this motor. Will these rods work or is this a screw up. Old motor has not been balanced and I turned it 6200 to 6500 regularly with no problems but it had stock 350 9/16 beam rods.

posted July 22, 2004 07:06 PM
Have ran them for years and would rather have them than the 350 rods. And you don't have to rebalance because you us the 305 rods thats a not true

Back to the Archives