69 head identification

[The_Jeremiah]

hey guys, im new to the oldsmobile engine thing. i can name all sorts of ford stuff, but im a noob when it comes to gm lol. anyways what i was wondering, is what heads i have, there is a big number 5 on the outside of the driver side head, this is a 350 out of a 69 cutlass, and the only other number i found was a small 4 next to the rockers on the passenger side head. this is a stock 2 barrel engine, what do you guys think ?

[Redog]

Well you have 5 heads which are rumored to be the best flowing small block Olds head there is. The best big block head is rumored to be the C head, unless you have the $6K and are able to find F,E,or D heads

Anyway, the 5 heads require leaded fuel due to soft valve seats. Many guys will say just to run 93 octane and you'll be OK, but I put in a lead additve every other fill up.

I doubt you have the W-31 heads but if you do you have a 2" intake valve and a 1.625 exhaust valve. The reg 5 heads are 1.875 on the intake and 1.562 on the exhaust. Both heads have a 68cc combustion chamber

Sorry to throw all that at you, but I myself just put a 1968 350 in my 85 Delta and I did a lot of reseach before installing it

[The_Jeremiah]

wow thats good news thanks a lot. i was wondering what size my valves were, needless to say since im building this engine up, the valves are getting a little bigger. they are not w heads i know that for sure. but can you tell me this ? are my studs 7/16 or 3/8. i cant go check them out right now so i cant check lol. what do you think ? and where is the best place to find a set of roller rockers for these heads ? i cant find any moderately priced ones anywhere. thanks guys

[The_Jeremiah]

does anyone know if 1.6" ratio roller rockers would work with the W specs cam?

[Oldsguy]

1.6:1 is the standard ratio on all Olds rockers as far as I know. I don't think you would need to go to roller rockers with a cam ground to standard Olds specs, the lift just wasn't that high, in any case not much more than .490 I think. Did you have a specific cam in mind?

[The_Jeremiah]

i wanted to go with the W-31 spec cam, which i believe to be is 233 duration for both intake and exhaust, and .474 valve lift for each. But i also heard that 230 duration for the intake and exhaust and lift of .490 for the intake and exhaust work great to. i found a good deal on roller rockers, and they are a 1.6 ratio, and mine are shot, thats why i was wondering. thanks

[Oldsguy]

If you have found a good deal then great. Are they Harland Sharp roller rockers? I have heard of people using those quite a bit. I went cheap and really didn't have to use them but I did. The 455 I rebuilt a few years ago have the comp cams roller tipped rockers. They work fine but as I said, I don't think I really needed them.

[The_Jeremiah]

I just realized, that my heads dont have studs. the rocker bridge has the bolts that run through each side, and thats how the whole mechanizm goes together. so i take it i need to put studs into my head to get rollers ?

[joe_padavano]

Originally Posted by The_Jeremiah

I just realized, that my heads dont have studs. the rocker bridge has the bolts that run through each side, and thats how the whole mechanizm goes together. so i take it i need to put studs into my head to get rollers ?

Correct. Unfortunately the Olds heads will have 5/16" tapped holes. If you use the Harlan Sharp rollers with a common shaft, they bolt directly to these tapped holes. Other rollers with 3/8" or 7/16" studs will require machining the holes for the larger thread size. Also, if you use individual rockers (as opposed to the Harlan Sharp common shaft rollers) you'll need to run pushrod guide plates, which in turn require machining the head for guide plate clearance and using hardened pushrods.

[The_Jeremiah]

Harlan Sharp rollers it is lol. thanks