Choice of two CR's...
Thread Starter
Joined: Jun 2004
Posts: 5,125
Likes: 4
From: Alexandria, VA
Choice of two CR's... I have the choice of running 10.3:1 or 11:1 in my new 408 block depending on whether I get the diamond flat tops with 2cc reliefs or the Wiseco's with the 8cc reliefs. I will be running my stock LQ9 heads and my 244/248 112 +4 cam. I also plan on doing a heads upgrade in the next year or two, as well as *possibly* a 100-150 shot of the giggly gas. Which compression would I be better off with in the long run? The diamond's would give me better numbers right now but might give me a bit too much compression with a future head upgrade. I'm having a hard time deciding and I want to order this block by the end of the week.
run a nice quench with .040 or .043 gaskets and run 11.3:1
The anti knock benefits of a proper quench will make up for the bump in compression's tendancy to knock on pump 93
The anti knock benefits of a proper quench will make up for the bump in compression's tendancy to knock on pump 93
Thread Starter
Joined: Jun 2004
Posts: 5,125
Likes: 4
From: Alexandria, VA
Originally Posted by smask04C5
scr of 11:1 is fine with that combination, imo diamond makes a better piston
You can get a flat top wiseco pistons with 2cc valve relief from an of the shelf piston. Or for a little more money you can have custom pistons made which is what i did. Flat top wiseco's w/ 2cc valve reliefs and lateral gas ports 
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
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
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Originally Posted by ArcticZ28
How much did those run you? And from who?
Originally Posted by ArcticZ28
From what I've heard, Wisecos are preferred for the most part over the Diamonds. Erik at HPE actually said they usually have to grind the skirts of the Diamonds a bit to keep them from hitting the Callies crank, but that doesn't make them of any lesser quality than the Wiseco's, just have to do a bit more work for them to fit. I am actually leaning more towards the Diamonds though to run a bit more compression. According to Erik, the quench with those is actuall going to be damn near perfect (~.040-.041) with a stock 6.0 GM MLS gasket and the Diamond pistons, as the pistons are built around .008-.010 out of the hole.
Stock mls are .060 How do you get .040 quench with .010 out of the hole?
Assuming 72cc chambers, you'll run 10.9 with gm mls and 11.4 with .040 cometics. I am running .043 SCE titan ICS gaskets for a sweet 11.3 and a nice quench of .033
Thread Starter
Joined: Jun 2004
Posts: 5,125
Likes: 4
From: Alexandria, VA
I'm just going with the info that Erik is telling me with his calculations that he's done. Any downsides to your running 11.3 compression? Is it a daily driver?
Originally Posted by ArcticZ28
I'm just going with the info that Erik is telling me with his calculations that he's done. Any downsides to your running 11.3 compression? Is it a daily driver?