Cam journal grove

[V SICKS]

Do all turbo 3.8's have the grove in the front journal?? Can you do without it if you use the hardened brngs with the grove behind the cam bearing? Also what is the difference in the 84 to 87 head bolts? I see a different listing for the different years.. my 84 has a 79 to 83 block appearantly with the 4885 heads from the later model..discovered all this after I bought it and was not what the seller said it was.. oh well... thanks.. mike

 

[GNVAIR]

all the production V6 blocks except the 109 blocks require a groove in the front journal on the cam. The 109 blocks have the groove in the block under the cam bearing. You can put a grooved cam into any block. But a non groove cam will only work in a 109. I believe all of the aftermarket cams have the groove. I found that 86's with the 109 can have either or. Most of the 87's I have owned had grooveless cams. I have one of the last new GM turbo cams and it has the groove.

 

[turbofish38]

My OEM 86 cam had the groove. That I remember because it was a PITA the first time I pulled it because of the way the front bearing was worn. And I'm 100% for sure all of the hot air motors I've done also have the groove in the cam. Somewhere GM has a bulletin on servicing the cam bearings. I'll see if I can dig it up. Hey I just found that bulletin. Heres the short version. All 109 blocks have the groove in the block. Either style of cam will work in that block. I've never looked at one of those early blocks so I cant say if there is a groove in the block.
Head bolts. 86 and 87 used torque to yield and 84-85 used reusable. If you tap the holes all the way than you can use the TTYs on the older blocks. You'd be money ahead by switching over to a good set of ARPs.GM used TTYs on most engines with composite HGs if that matters. I've had good luck using the non-TTY on my hot airs with the steel shim HG.