Thats interesting coz, i ve done a fair bottom research on gm squarebody forums, diesel place. Almost all truck and or diesel forums, and while there is a split between do you'll be fine, vs don't do it you'll blow it up,
Here's what I've noticed
Stock: Just oil feed & drain, manifolds intake n exhaust) and turning up fuel. Still head bolts nothing else change. 6 psi and you're fine. Some claim more but most I've seen in reading forums is 6.
Arp head studs and of course new head gaskets: claims of 10 to 12 comfortably.
More than that then guys are talking intercooler, and that coolant passage at rear of block with those two flange, passenger side blanked and old style 6.2 (like mine) have the glow plig controller screwed into to coolant passage in block, well as cross over between that. Allegedly, 15 psi n more.
This is a general consensus.
I do appreciate to earlier answers to this post, sharecropper saying a lot of guys doing this and then send it uo to 14 psi boost but never really hear from them again, did they cook the engine? Did lower end go for a sh*t?
3 psi is pretty small, I'm not arguing your point. I'm wide open to all suggestions. And I know 6.2 isn't meant for power, but 3 psi is crazy low.
Another thing I came across that not many users on any foru.s mention is, engine girdle. To protect to lower end. Some say don't bother, waste of time etc etc etc... the one specific to 6.2 n 6.5 is on the pricy side. But it does come with the studs. However, scamazon dpes have one for small block chevy for a lot cheaper.
Aren't the 6.2 n 6.5 just a diesel powered sbc? As in, in the 80s during fuel crisis gm was in a rush to push out an economical diesel and they basically took the SBC and gave it IDI heads, an injection pump and called it a day, or am I in left field? (Speakingnof baseball references, world series is interesting this year BTW, go Jay's!)
So, hypothetical build here (and expensive)
1. Fluidampr harmonic balancer.
2. Arp head studs and a thicker new gasket, installed dry, some guys talk about copper spray, but last I checked, head gaskets go on dry.
3. Machined heads with a bit taken off to lower compression ratios a bit
4. Engine girdle with studs,
5.Finally say, 6 to 8 psi boost.
Thats basically all the mods you can possibly do to strengthen a 6 2 (i skipped the 6.5 pistons swap coz I don't wanna go there) again, hypothetical build here.
