1967 L68 pushrod size

[Tim S.]

Is it correct that a 1967 427 L-88 hydraulic engine had 5/16 pushrods?
Thanks
Tim

[Stuart F.]

Re: 1967 L68 pushrod size

You mean L-68 Hydraulic don't you? I can't imagine any L-88 with Hydraulics, but the 5/16" push rods sounds about right. Let's see if some of the experts weigh in on this.

Stu Fox

[Michael H.]

Re: 1967 L68 pushrod size

Is it correct that a 1967 427 L-88 hydraulic engine had 5/16 pushrods?
Thanks
Tim

Tim, as Stewart noted, I assume you meant L-68, not L-88.

It's true that some VERY early 67 390 and 400 HP 427 engines were assembled with the small 5/16" pushrods. These engines were assembled in August of 1966 for the 67 model.
If I remember the date correctly, as of 1 Sept 1966, the pushrod size was changed BACK to the larger 3/8" size that was used all through the 1966 model year and then continued through the 67 model and beyond.
Again, if I remember correctly, the note on this change was shown as occuring on engines with a pad date stamp of 1 Sept and later.
I don't know how many engines with the small dia pushrods were assembled but I suppose that at least the first few weeks of 67 Corvette production may have a pre 1 Sept 1966 engine build date.

The pushrod guide plates on early heads would also have been changed to match the small pushrod of these very early 67 engines, then changed back to the larger size on engines built a few weeks later.

[Tim S.]

Re: 1967 L68 pushrod size

Sorry, yes an L-68 400 HP engine. Interesting this car has the 5/16th push rods it is SN101539. I thought it was a mistake but perhaps not. I think I will change them to 3/8" anyway!
Thanks
Tim