BBC valve guides

[speedmachine]

Hello,
Would any one happen to know a part number/name for a BBC 990 casting intake valve guide? Head is dated 1973. I am having a hard time getting them from parts company.
I keep receiving guides that are too small OD. Any help would be appreciated. Thanks.

[GOSFAST]

Hello,
Would any one happen to know a part number/name for a BBC 990 casting intake valve guide? Head is dated 1973. I am having a hard time getting them from parts company.
I keep receiving guides that are too small OD. Any help would be appreciated. Thanks.

Available from SBI and others, we happen to have Manley's on the shelf here!

The SBI number is 140-1973, the Manley's number is VG973.

Thanks, Gary in N.Y.

P.S. The dimensions are:.6255" O.D., 2.420" long, and .3735" I.D.

[speedmachine]

Thanks,
I tried one of those but it is entirely to small, I am not sure why these guides are so large. Most bbc heads I do use the 140-1973. I would measure but was destroyed by the valve and finished it off pressing it out. I will try to measure the hole

[Newold1]

Sounds like what you are describing is some monkey screwing up the heads getting the old guides out and then over boring the holes out and using some oversize guides?

Measure the holes and call CHE and have them find in their inventory or make you some custom sized guides. Make them a few thou oversize and heat the head and nitrogen the guides and then install them. Seems with iron guides in iron heads does not take much of an oversize like you see in aluminum heads.

[Charliesauto]

CV Products offers bronze blank guides in .750" OD. The seal surface is finished to .531" OD. If you have a decent lathe, you can place the seal end in a 17/32 collet, support the other end with a live center and machine them as needed.

[ProPower engines]

Hello,
Would any one happen to know a part number/name for a BBC 990 casting intake valve guide? Head is dated 1973. I am having a hard time getting them from parts company.
I keep receiving guides that are too small OD. Any help would be appreciated. Thanks.

If you are doing BBC heads on a regular basis and need to press out the exhaust guides I have been using a .627" od guide to avoid using the jobber stepped middle guides.
I have found that by just reaming the existing hole to .625" and using a common .6275 od cast guide it avoids any leaking at the water passage in the older heads.SBI has some available SBI# 140-6905 that are best suited and easily linered after for a honed valve job. They are intended for a diesel but they have the same stem size as a BBC uses and long enough that they can be cut down to suit you seal needs as well.

I see this all the time on marine heads and the only way to save them most times is a larger OD exhaust guide.
I believe there is an Pioneer # for that head 00972.

I don't even bother using the stock OD on any BBC iron heads I just go straight to .625 ID and use a .6275 OD guide to avoid them ever leaking.
Seem too many guides replaced over the years that leaked and had to be done again