L72 Con Rod Question
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Instructor
Joined: Aug 2005
Posts: 157
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L72 Con Rod Question
I was trying to find out about when the rods changed in the HP engines.
I was told that 65 to 68 BB s basically had the same rod except for the bolts
I have heard that they are small bolts and nothing special about the rod exept the baron steel bolt.
Are the rods in the l72, 89 and 88 the same as the regular 3/8 rod from 65-68?
I was told that the 1st HP rods "l88" were made in 69 with the dimple rods which were later changed when the LS engines came out.
Does anyone know the low down?
I was told that 65 to 68 BB s basically had the same rod except for the bolts
I have heard that they are small bolts and nothing special about the rod exept the baron steel bolt.
Are the rods in the l72, 89 and 88 the same as the regular 3/8 rod from 65-68?
I was told that the 1st HP rods "l88" were made in 69 with the dimple rods which were later changed when the LS engines came out.
Does anyone know the low down?
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
You are correct, the early big blocks had 3/8" rod bolts and the L-88 in mid 68 (I think, 1969 for certain) went to the bigger/stronger 7/16" rod bolts. More exotic materials were used in the 1970 LS-7 program (boron steel bolts) but, I think all the L-88, ZL-1 and LS-6 rods had the same stlye 7/16" bolts (ARP bolts are superior to OEM Chevy bolts.) This being said, I wouldn't run a B Block chevy past 6500RPM without some decent rods in it. There are numerous accounts of connecting rod failures in early L-88 motors during endurance races. Manley, Crower, and Carrillo all make decent rods for your motor, play it safe if your going to wind out the motor.
Last edited by Solid LT1; Dec 9, 2007 at 09:18 PM.
