6.5 Precups - Power -OR- Economy?

[Chevrolet4x4s]

which pre cups would be good for a mild to medium twin turbo intercooled 6.5 built for economy? Also what years did the 6.5s get roller cams?
Shane

[DmaxMaverick]

which pre cups would be good for a mild to medium twin turbo intercooled 6.5 built for economy? Also what years did the 6.5s get roller cams?
Shane

I'd suggest using 6.5 TD cups. The gain/risk with N/A cups won't wash.

6.2/6.5 engines have always had rollers.

[Chevrolet4x4s]

I'd suggest using 6.5 TD cups. The gain/risk with N/A cups won't wash.

6.2/6.5 engines have always had rollers.

Well I shouldnt have to pull the heads then.Glad to hear that its a roller cam.

Also which years of 6.5s had the 18 to 1 pistons and is there a casting number on the engine that will tell you if it is the 18 to one engine....Its a late 95 or a 96 engine
Thanks
Shane

[MaxPF]

No factory 6.5 ever had 18:1 compression. 6.2's and early 6.5's had 21.3:1 compression. Later they dropped the compression to 20.3:1. I don't remember when the change was made though...

[Chevrolet4x4s]

No factory 6.5 ever had 18:1 compression. 6.2's and early 6.5's had 21.3:1 compression. Later they dropped the compression to 20.3:1. I don't remember when the change was made though...

Aaaw shucks further proof not to take everything in a wiki to the bank
http://en.wikipedia.org/wiki/Detroit_Diesel_V8_engine on the 20.3 to 1 would 10-14 max psi intercooled with close watch on egts be ok?
Shane

[More Power]

Actually....... AM General/GEP currently builds 18:1 6.5's on an infrequent basis. They all go to the marine vendors.... The 18:1 6.5's that Peninsular, Marine Diesel, and other marine vendors offer are all factory built as 18:1 engines. GM never offered them in their trucks/subs though.

Jim