ok so i am in the process of building my 97 lt1 and need help with the valvetrain so heres what ive got.
i just finished rebuilding the bottom end (stock internals)brand new!!
and i bought a CC503 cam for it (installed)
i P&P my 1994 stock heads(flowed 270/185)
i want 1.6rr rockers but dont know which ones to go with (need advise)
and what springs should i use for that cam and rocker setup?(need advise) i am looking at he crane cams 10308 but cant find specs will these work?
also what valves should i go with?(size wise)
and if i go to a thinner head gasket like a .038 instead of the .049 will it still be DD capable? i think it would be like 11.7.1 with thak gasket

ohh and this is a DD 6-speed with 373 gears please help!!!!!

 

The Crane Spring Kit 10308-1 contains spring 99893, dual spring
o.d. 1.460
I.d. .800
seat 120 @ 1.875
open 425 @ 1.180
Coil bindO 1.180
Max lift: .640

Check your cam spec card for the CC503 for recommended springs, pressures, etc.

I suggest going with a full Roller Rocker, non-sa, guide plates, hardened prs. If you go with other than stock gaskets you are going to get into measuring for different sized prs to get the correct geometry. Would not bother going with larger valves, since if you do, you will have to have head work to unshroud them.

Frankly, I'd go with stock gaskets and stock valves. JMHO

 

why non-SA also i did not get the cam card with it. and will the lt4 springs work or do you know? ohh forgot to add also have pored intake as well and do you have any idea what kind of power i may put down?

 

Did you enlarge the valve spring pockets when you did the head work? If you did
this will provide more options for valve springs and spring seats.

Also use the search function and you will find a ton of information on valve
springs.

 

no i didnt touch the pockets. what about rockers? and what kind of gas mileage will i get with 373 gears? i have 342s now and get around 30mpg on hyw

 

Your spring seats are big enough to support any spring that the 503 would need. Brand of RRs is a personal choice. I have Crowers, but they are spendy. I would go with a good brand name, Steel RRs. Non-SA Rockers are supposedly better for control, esp. at High Rpms and aggressive cams. I have a small cam and use SA RRs.

I don't know what DD 6-speed means. But if you are just talking about an M-6, then 3.73 is the way to go if you don't like the uselessness of the 6th gear. I have 4.10s. If you are getting 30 MPG cruising in 6th gear and you use 6th gear alot and you drive mainly on hwys without hills, then it's a matter of whether you like the overdrive 6 gear. If you are concerned with gas mileage, you have the wrong hobbie.

going from 3.42s to 3.73 increases the torque to the wheels by 9%. Goinng to a 4.10, 20%. JMHO

 

Go with the PAC springs, forget the part number, but their the equivalent of 918 Comp Bee Hives, and their an excellent spring for that cam.

Rockers, I say go with steel NSA ones, and either ISKY adjustable guideplates or the LT1 guide plates from GMPP.

An M6 thats Daily Driven, would be fine with 3.73's. You might loose 2 MPG at highway cruising ... Even 4.10's arent that bad since we have a double overdrive transmission lol. How much time do you spend driving on the highway?

 

Go with 4.10's, what little affect they have on freeway mpg's will be made up with the smile on your face during take-off.