Open Road

These are exact reproductions of Mike Simard's head and block stud kits. I started off by taking my set of Simard studs and had them destructively tested at a local metallurgy lab. They did a composition test so I know exactly what material was used. I also had transverse hardness testing done where they cut studs in half and did hardness testing 1mm apart thru the entire studs to determine if they were through hardened or just surface hardened, as well as documenting the hardness level.

Threads are rolled just like the original. Mike was super picky about the washers for the 12mm studs and only used the factory Porsche washers which run over $4 each. I made custom washers to the same spec because I needed more washers for these kits than Porsche had in stock world wide. The 10mm washers were custom made as well since the factory 10mm washers have since gone NLA. The same process was followed to have the washers made by having the local lab complete hardness tests as well as material testing and certification.

It goes without saying that certified lab testing is not cheap. I spent several thousand $$$ just to have the testing done.
They are identical to the original Simard studs. I had to spread the lab costs, the development costs as well as the manufacturing costs across these sets which resulted in prices higher than I wanted but it is what it is. When the original versions were available in 2010 they ran 650 per set.

Lower block stud kits are $599



Head stud kits are $699



10 sets are made only 7 sets left.

If anyone purchases a set of head studs and block studs at the same time I'll discount $100 off the order.

And yes I'm running these in my own engine.

I would suggest adding a pointer to how to purchase info.

They can be located in my online store:

https://928-innovations.mybigcommerce.com/

Under the Engine section.

Will the lower block stud kit work together withe the girdle reinforcement plate that Simard also made?

As far as I know they should. These are made to the exact same dimensions as the originals. There is a thread over on RL talking about it.

https://rennlist.com/forums/928-forum/3 ... dle-2.html

I wish I had one of his main girdles.

so it looks like the lower block studs as well as the longer head bolts for the 89 and later blocks are all NLA.

I don't want to hijack the thread but a quick question. For those of us who are contemplating pulling their engine and replacing head gaskets, what are the thoughts on keeping original the lower block studs if it turns out that bearing work needs to be done? Are those studs under the same kind of destructive forces that exist on the head studs, thus necessitating replacement vs reuse? I don't recall ever seeing a thread on replacing the lower studs as a matter of course on a rebuild.

jschiller wrote: ↑Thu Nov 13, 2025 7:52 pm I don't recall ever seeing a thread on replacing the lower studs as a matter of course on a rebuild.

And neither have I. (Seen threads nor replaced them.)

maddog2020 wrote: ↑Thu Nov 13, 2025 5:23 pm ... the longer head bolts for the 89 and later blocks are all NLA.

$35 each but still shown as available. But, for the '87-'88 not so much.

try to order a set....

I had a discussion with a local shop about the lower block studs. Most shops don't want to try and remove them from fear of damaging the block. They are concerned about the age, but since none of the lower block studs are available that is yet another reason to not want to remove them.

However if you are going the Nikasil route then you have no choice as they must be removed for the nikasil process.

I built a few stroker engines with 30 year old lower block studs but didn't like doing so. One of our more colorful members from the other site is doing everything he can do poison the waters without knowing much about them, or even having a set. the irony is he talked these up years ago but seems to have forgotten it.

They seem to be very poplular, as most of my sales have been to customers in Europe and one customer bought 4 sets of uppers and lowers.

maddog2020 wrote: ↑Mon Dec 08, 2025 3:34 pm ...One of our more colorful members from the other site is doing everything he can do poison the waters without knowing much about them, or even having a set. the irony is he talked these up years ago but seems to have forgotten it.

Made me look. But, I'm not sure who you're talking about. Unless it's Fred. I didn't read his posts. I can’t read them actually. My brain slides off them ever since the big coolant thread when he'd contradict himself in the same post.

it's not Fred. I tune out on those too. It's GB on his facebook page.