Possible head bore problem?
Thread Starter
Teching In
Joined: Nov 2003
Posts: 23
Likes: 0
From: Memphis, TN
Possible head bore problem? Ok, so I just purchased some Absolute Speed stage 2.5 5.3L heads from a friend. I knew he had a 370 c.i. motor, but I thought it was just stroked. I just measured the heads, and it appeard that the bores have been machined out to accomodate a 3.925" bore. Would there be any problem mating these heads to my stock bore/stroke bottom end? I'm sure it's not perfectly ideal, but I figured .02" on the diameter probably wouldn't pose a problem.
Your thoughts?
I assume it will still use a stock bore sized head gasket.
Thanks!
Your thoughts?
I assume it will still use a stock bore sized head gasket.
Thanks!
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Originally Posted by KingWalrus
30 thou bigger than 3.925? Why? I'll take your word on it; I'm just trying to learn in the process!
Thanks for the responses, btw.
Thanks for the responses, btw.
Trending Topics
Thread Starter
Teching In
Joined: Nov 2003
Posts: 23
Likes: 0
From: Memphis, TN
Are GM replacement gaskets available in multiple bore sizes, or would I need a cometic or something similar? I have an order placed with Scoggins Dickey on some stock gaskets, but I don't think they've shipped yet. I'll give em a call.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Originally Posted by KingWalrus
Are GM replacement gaskets available in multiple bore sizes, or would I need a cometic or something similar? I have an order placed with Scoggins Dickey on some stock gaskets, but I don't think they've shipped yet. I'll give em a call.
All LS1 are 3.910 (IIRC)
Thread Starter
Teching In
Joined: Nov 2003
Posts: 23
Likes: 0
From: Memphis, TN
So it looks like a Cometic is in my future unless the 6.0L gasket would suffice. Now if I could just get a hold of SD! ****, maybe I'll just bore the engine to match the heads. This makes sense...
Thread Starter
Teching In
Joined: Nov 2003
Posts: 23
Likes: 0
From: Memphis, TN
That's interesting. Is that true for all LS1's or just the 97-98 motors? Does going beyond 3.905 require resleeving? I'm kinda surprised GM didn't put more "rebuildability" into the engine.
Thread Starter
Teching In
Joined: Nov 2003
Posts: 23
Likes: 0
From: Memphis, TN
Ok, just talked to the guys at SD. I got some Cometic gaskets with 3.930" bore and .051" thick. I can't find the stock head gasket thickness anywhere. I swear I remember reading somewhere it being like .036" or so. This gasket is a bit thicker, but it will help with P-V clearance. These heads are milled 10 thou, and I may have them cleaned up with an additional 5 thou taken off.
Thanks for the help!
Thanks for the help!
Thread Starter
Teching In
Joined: Nov 2003
Posts: 23
Likes: 0
From: Memphis, TN
Found the factory head gasket thickness: .052". These cometic .051" gaskets will have little to no effect on quench, etc. So long as I still have some P-V clearance, I think I'm good to go.
