I think with an older SBC 2 bolt main blocks the upgraded main bolts are a must. I think with a LS 6 bolt mains you are ok with stock main bolts. Again it a lot less risky are 700hp then it is at 1000hp.

Why engine builders/race team hate stock bolts.
Stock bolts are massed produced, the main body is cold or "warm" formed into shape then the bolt/stud is move to a thread roller that cold forms the threads. Both process are extremely fast as you can imagine because GM would need millions of these. When ever you cold form anything there is a small chance you could have a bad fold in the process. This means the item could have a built in crack.

Bad folds in product can be detected easily but small surface folds are more common. GM designs the bolts/studs larger then they need to be to compensate for these small defect. These small defect cause what is know as a stress riser, how bad the defect can hurt the bolt depends on the depth and the location. The more you stress the bolt the more the stress riser can cause a failure. If you have 16 defect free rod bolt you can do amazing thing with stock bolt and the after market bolt are only slightly strong. But also keep in mind I am sure GM has rod bolt failures in stock engine also due to bigger manufacturing defects. They do a risk to cost analyses and try calculate the cheapest bolt size vs average defect and try to hit one in a million failures rate.

To avoid these defect you just need to buy a extruded rod and turn it on a screw machine/CNC lath. This is how ARP makes its bolts and how every single bolt in a jet engine is made. From a production point of view machining a bolt like this is easily 20x the cost. To put it in perspective a screw machine can thread a bolt in 15 seconds. A thread roller can do 200 pc per minute.

 

I know it's been a while since I last posted. I haven't had a lot of time or the funds to get things going. But here's and update. I started the cage in the Camaro. It's coming along nice. I only have the one pic, but I'll definitely post more when it's finished.

As for the engine, It's been bored to 4.030, I went with forged diamond dished Pistons (CR should be around 9.5:1), forged eagle rods with ARP bolts, and keeping the stock crank. Everything is getting balanced now and I should be picking it up next week to assemble. I'll definitely upload picks of the assembly.

 

looks great cant wait to see the engine

 

Got the bottom end assembled!! Looks good

 

looks great from before ,now your puting this a 6.0 bored to 6.7 408 ,in a 99 bace model ,,? did you look at the thread with lsx 5.3l build ,he knew alot more then he shared ,but he may have alot more info to help you with it,for some reason its posted in general under 01 camaro v6 to v8 where he put an lsx 5.3l in a bace car 5/13/2015 ,clinebarger may be some help to you ,he made it look easy ,but he was not building a hot rod just a speeper of sorts

 

As much as I'd love to have a turbo charged 408. I have come to reality with my budget. It's got the stock crank and it's been bored over to a 4.030. I think that makes it a 377ci. Still going twin turbo, not changing that part. Lol And yes, I'm dropping it in a 99 base model camaro. I'll be getting the car soon from my friends shop. Hopefully this weekend we'll have the cage done. My work schedule this summer through a big wrench in my timeline. But progress is still progress.

And thanks for the write up. I'll have to check it out and see if I can get some good ideas.

 

Installed the Stage 3 Turbo cam from Tick performance. Got a new HD LS2 timing chain and a Melling High volume pump. Just waiting to come across an F-Body or equivalent shallow oil pan to button up the bottom end. I also was able to trim the grill out of the bumper to allow more airflow to the future intercooler. Surprisingly, it's not flimsy. I thought I would definitely have to support it, but so far feels good.

 

looking good

 

Thanks!!! It's finally coming together. Just picked up an f-body pan today. So it'll be nice to finally button up the bottom end.

 

ya thats a 6.2L wich is what most of the new ss cars have now as well as some mustanges too,have the 376 very popular engine