bBody22

As the title states are the Lt1 head bolts torque to yelid?

afterburner82

iTrader: (2)

The stock bolts are if I am not mistaken. Aftermarkets like ARP are reusable.

96capricemgr

iTrader: (1)

A lot of debate on this and I don't think there is a proper decisive answer. IMO if some are TTY it would have started around 96-97, a lot of folks have reused stock bolts and I believe at least on the earlier years GM approved reusing them once.

Pretty sure the 96 motor I tore down had a different looking bolt than the several 94-5 motors I have torn apart.

gregrob

iTrader: (8)

I've heard 93-95 are not, 96+ are. I've reused 94 bolts

GIZMO

iTrader: (8)

My 1995 Formula had TTY bolts.

95LTXZ28

iTrader: (19)

My 95 camaro had TTY bolts as well. I replaced them with ARP's which I believe are re-usable. I always look at it as its cheaper to just buy new ones, then tear it down again for a over stressed head bolt that may cause some expensive problems.

gregrob

iTrader: (8)

How did you guys determine they were TTY

96lt1m6

iTrader: (31)

For the price of ARP head bolts, i would suggest swapping the bolts and know you can reuse them.

shbox

I say the bolts are not TTY. I have researched this many times and find nothing to indicate they are. The torque/angle method for tightening (does not require TTY bolts) was introduced in the factory manual for 1996. The long and short bolt part numbers for the head bolts never changed 93-97 (the medium bolts did change p/n for some reason). They would not have mixed TTY and non TTY bolts on the head and they could not have used TTY bolts in early years without specifying the torque/angle method of tightening they must use.

My 95 had no TTY bolts..

WS Sick

I know for a fact the 93 and 94s are not TTy and the 97s are, The 93 and 94s had a larger head with a washer and the 97s did not have a washer but had a shoulder below the head.

shbox

I also have not seen anything in the factory service manual that states they are TTY. I have a factory manual for a different 97 GM car that uses the 3.8 V6. It goes out of its way to point out the TTY head bolts. You'd think the LT1 manual would too. So, everyone with 97 factory manual take a look and report back.

Pretty confusing that the stock bolt part number is the same 93-97, but later years used different bolts? Does not make sense to me.

I guess this is why this question never gets resolved.

Spartan7

iTrader: (7)

I don't have the 97 manuals, but my 96 ones make no mention of TTY head bolts. Just thought I'd throw that out there.

RamAir95TA

iTrader: (2)

I think since the info about the OEM head bolts seems to be wishy-washy, it's a good idea in general to just replace them.

96capricemgr

iTrader: (1)

shbox, part numbers are superceded so often I would not count on PNs to figure this out.

My experience is along the lines of what WS Sick said.

Tomorrow I might even be able to find examples of each.

I will say if in doubt replace.

I do wish this question could be answered more definitively.
I definitely trust GIZMO's input on things so I would throw out the possibility of a mid-year change.

shbox

Part numbers aside, the manuals (or anything I have seen in print) suggest nothing of TTY. I'll stick with my theory until I can see there is something that looks like more proof to me.

I agree with replacing with ARP bolts in any case. I did it on mine.

96capricemgr

iTrader: (1)

Can you explain several of us having reported finding different style bolts in early vs. late motors?

I understand your thinking but at the same time the manual lists thermostat housing torque in ft.lbs so it is not to be completely trusted, a TTY note could have been forgotten.

shbox

Well the manual was wrong in one place and right in another on those, bolts, but typos happen. It does not take a genius to figure out a little bitty bolt does not take 89 ft. lbs of torque. I would say parts books are often more accurate than the manual.

I know what you are saying and I am not sure that everyone would know a TTY bolt from a regular bolt if they saw one. I am not sure I could prove it, myself, not having worked with a lot of them. I have not torn down a late model or seen pics or comparison of the bolts people are talking about. I am also not calling anyone out on it. I sometimes like to see things with my own eyes to be convinced. If it is so, it is so or we can leave it at some are and some are not. LOL.

Until this thread, I have not seen anyone claim they pulled out TTY bolts from an LT1. They only said "somebody told me they were supposed to be TTY. Is it true?"

gregrob

iTrader: (8)

Just because they look different on certain years doesnt automatically mean they're TTY.
I agree with replacing them though, cheap insurance

shbox

That's kinda what I'm saying. Suppliers can change and so can the look of the bolts.

Choppers

iTrader: (60)

I have a set of ARP head bolts for sale. They are reusable. LMK if you would like them. Check out my for sale thread.