I have an 88 Duke and am in need of new rocker bolts as some of them have rough threads. Being this motor was rebuilt by the previous owner, I am seeing some odd things. It looks like they took a spare set of pushrod guides and cut the guide portion off and stacked washers in addition to a stock pushrod guide...presumably to take some preload out of the lifter??? Or are there two different style rocker arm bolts? I see that The Fiero Store has rocker bolts, but they only list for the 84-86. I know the rocker arms are the same for all years, so is the shoulder length different?

https://www.fierostore.com/...px?s=63103&d=184&p=2

Rock Auto lists bolts for the 88, but when you try to add to cart, they are not available.

I'm almost positive Big-Block chevy parts will work and they are available over the counter at NAPA or elsewhere, probably just have to go take a look at them and compare, but i'm 90% sure

Iron Duke has metric threads for the rocker bolts. I could redrilled the head or use the ARP metric to SAE studs but they aren't cheap and I already bought Duke stuff.

I have two options at this point. Getting some adjustable pushrods made up or have a machine shop buddy make some hardened machine washers to put under the bolt to "loosen" or under the bolt head to "tighten". I will be running a reground cam so I may need to tighten up.

GM LS series rocker arm studs are metric. Combine that with the older chevy inline six rockers arms and you have an easy to install adjustable valve train. A search on this forum should bring up a thread about this.

There are two different length rocker studs for the duke. I think the early ones are about an 1/8th inch longer.

quote Originally posted by Fiero STS: There are two different length rocker studs for the duke. I think the early ones are about an 1/8th inch longer.

It seems there are two different lengths, but I would suspect the early ones to be shorter since the previous owner spaced them out. I definitely have a late head too. Who knows...I will just mock it up and see what I come up with. There are two different length pushrods too. Maybe they used the wrong pushrods and accounted for it with the washers?? The joys of working behind other people...

[This message has been edited by regal7point5 (edited 03-15-2017).]