1994 Tc/head/header bolt questions
10-08-2015, 09:37 AM
#1
Instructor
Thread Starter
1994 Tc/head/header bolt questions
1. I'm going to do a TC change. Is it necessary to get new flex plate bolts?
2. I'm sending my heads to LLoyd Elliot. I've read new head bolts are a must. Some say that they have the TTY head blots. Then, some say not in the LT1, just in L98. Can anyone clarify, does a 1994 have TTY, and do I need to use new bolts?
3. Lastly, I have a new set of LT TPIS headers. TPIS headers supposedly take stock exhaust manifold bolts. Mine are a little ratty and I want to replace them. I called TPIS they aren't much help. I checked ARP and can't find the size I need. I checked Fastenal, they have the correct size but only in zinc, no SAE grade. The local chevy parts says they take M8 x 1.25x45, but they want $9.95/ bolt.
Yes, I've searched the forum trying to find answers. Thanks for any advice/help.
2. I'm sending my heads to LLoyd Elliot. I've read new head bolts are a must. Some say that they have the TTY head blots. Then, some say not in the LT1, just in L98. Can anyone clarify, does a 1994 have TTY, and do I need to use new bolts?
3. Lastly, I have a new set of LT TPIS headers. TPIS headers supposedly take stock exhaust manifold bolts. Mine are a little ratty and I want to replace them. I called TPIS they aren't much help. I checked ARP and can't find the size I need. I checked Fastenal, they have the correct size but only in zinc, no SAE grade. The local chevy parts says they take M8 x 1.25x45, but they want $9.95/ bolt.
Yes, I've searched the forum trying to find answers. Thanks for any advice/help.
10-08-2015, 10:43 AM
#2
Le Mans Master
I would go ahead and reuse the TC bolts, but use Loctite BLUE on the threads.
Try your local hardware store for your header bolts. Since you know the size you should be able to find them. M8 x 1.25x45 is probably for cast iron exhaust manifolds and are therefore longer (45). The 45 long bolt will be too long for your headers. The bolts listed by ARP and others are listed as 25. Your headers are most often 1/4" flat stock bolted to the head and will use the shorter bolt.
Try your local hardware store for your header bolts. Since you know the size you should be able to find them. M8 x 1.25x45 is probably for cast iron exhaust manifolds and are therefore longer (45). The 45 long bolt will be too long for your headers. The bolts listed by ARP and others are listed as 25. Your headers are most often 1/4" flat stock bolted to the head and will use the shorter bolt.
10-09-2015, 07:05 AM
#3
Instructor
Thread Starter
TPIS
I will try a hardware store. TPIS headers use the same length as stock exhaust manifold. They are unusual in this way. Supposedly they do this so accessories like AC compressor can bolt right on, plus bolts are easy to get to.
What about head bolts on a 1994. Does anyone know if they can be reused?
I would go ahead and reuse the TC bolts, but use Loctite BLUE on the threads.
Try your local hardware store for your header bolts. Since you know the size you should be able to find them. M8 x 1.25x45 is probably for cast iron exhaust manifolds and are therefore longer (45). The 45 long bolt will be too long for your headers. The bolts listed by ARP and others are listed as 25. Your headers are most often 1/4" flat stock bolted to the head and will use the shorter bolt.
Try your local hardware store for your header bolts. Since you know the size you should be able to find them. M8 x 1.25x45 is probably for cast iron exhaust manifolds and are therefore longer (45). The 45 long bolt will be too long for your headers. The bolts listed by ARP and others are listed as 25. Your headers are most often 1/4" flat stock bolted to the head and will use the shorter bolt.
What about head bolts on a 1994. Does anyone know if they can be reused?
10-09-2015, 07:26 AM
#4
I believe I'd buy new converter bolts. There's only three so if you bought and discovered an issue with one when removed it would save you a trip to the dealer later. BE PREPARED !!!
Head bolts will be debated likely "forever" but I don't believe they're TTY BUT the torqueing procedure was revised in later LT1 years and there are what's considered maybe "in car service" and maybe an overhaul procedure, depends on what you read and from who. Mercury Marine I believe even issued a TSB related to head bolt installation.
I believe the purchase of a full set of "premium head bolts" is likely a very good idea. Required, probably NOT but I'd think just a very good idea.
I'm not familiar with the TPIS product but the use of OE hardware, if that's suggested sounds like a good idea. I don't know how many studs are used but I'd think OE a + that allows easy mount of OE accessories.
I believe you need to "RECHECK" the information passed on to you by the dealer regarding the manifold to cylinder head bolts. I believe it's incorrect. If you wanted new I believe I'd maybe do OE/GM because of material choice and having the flanged head but maybe they're NLA so I'd shop being cautious of material and make sure you're buying "hex flanged head" hardware.
I would think the bolts are likely 3/8-16 X 2 1/8 using GM specs. I'd consider maybe just a clean-up of the originals maybe unless "really ratty". A brass brush?
Head bolts will be debated likely "forever" but I don't believe they're TTY BUT the torqueing procedure was revised in later LT1 years and there are what's considered maybe "in car service" and maybe an overhaul procedure, depends on what you read and from who. Mercury Marine I believe even issued a TSB related to head bolt installation.
I believe the purchase of a full set of "premium head bolts" is likely a very good idea. Required, probably NOT but I'd think just a very good idea.
3. Lastly, I have a new set of LT TPIS headers. TPIS headers supposedly take stock exhaust manifold bolts. Mine are a little ratty and I want to replace them. I called TPIS they aren't much help. I checked ARP and can't find the size I need. I checked Fastenal, they have the correct size but only in zinc, no SAE grade. The local chevy parts says they take M8 x 1.25x45, but they want $9.95/ bolt. Yes, I've searched the forum trying to find answers. Thanks for any advice/help.
Yes, I've searched the forum trying to find answers. Thanks for any advice/help.I'm not familiar with the TPIS product but the use of OE hardware, if that's suggested sounds like a good idea. I don't know how many studs are used but I'd think OE a + that allows easy mount of OE accessories.
I believe you need to "RECHECK" the information passed on to you by the dealer regarding the manifold to cylinder head bolts. I believe it's incorrect. If you wanted new I believe I'd maybe do OE/GM because of material choice and having the flanged head but maybe they're NLA so I'd shop being cautious of material and make sure you're buying "hex flanged head" hardware.
I would think the bolts are likely 3/8-16 X 2 1/8 using GM specs. I'd consider maybe just a clean-up of the originals maybe unless "really ratty". A brass brush?
Last edited by WVZR-1; 10-09-2015 at 08:58 AM.