I am dialing in a McLeod bellhousing and have determined the following measurements:

9 o'clock = 0.00 (where I started)
12 o'clock .010 in
3 o'clock = .002 in
6 o'clock = .007 out

It appears I need .004-.005 offset dowels. I had the block saver plate and bellhousing attached with the 6 bolts that go in the rear block face. Will adding the bolts that hold the BH and plate together at the bottom change my measurements? Also, where can I but Moroso dowels.

On a side note how on earth did the auto manufacturers get away with not doing this on millions of cars???

I don't believe the plate bolts will change it much but easy enough to install them all. I always thought the Lakewood specs on bellhousing alignment were a little on the tight side. I believe Mcleod and CF use the same specs. <.005 runout and <.002 parallelism. Did you also check for parallelism? I believe .002 or less is an insane goal but some here have obtained it.

Awhile back I mocked up a stock cast iron bellhousing and measured .017 for runout and parallelism both. This was a good test sample because I had personally power shifted with this bellhousing to 6500-7 on numerous occasions (NOT RECOMMENDED):clonk: .

Wish I had the time to do a larger sample and get paid for it:D I would like to get some average numbers on the OE stuff.

Your on the high side IMO, Lakewood also makes a dowel pin relocating kit that works well.

i thought the mcleod b/h was supposed to be more accurate than the lakewood, but doesnt seem so unless its off on the block-one thing i found was on the inside if theres some roughness it will throw off the dial ind.
also, some of the cheapie dial inds. move around also(seems like you cant buy anything in this country thats made accurate anymore)
i have used the long dowels with a weld ring to locate the b/h, they work pretty good
as a side note, i ck'ed my stock one b4 rem., it was 2.5-3 out, pretty dam accurate

Apparently McLeod check runout at the factory because mine has a sticker with 8 radial measurements showing .000 to .001. I think the issue is with my block. How do I check parallelism? Where does the dial indicator go?

The McLeod bellhousing come pre-dialed in from the factory - I have personally seen their equipment that checks for correct alignment before they apply the SFI sticker showing the readings. After that they ship them out. It is possible that you measured slighly wrong or you rdial indicator is not 100% accuarte. The only other thing I could think of would be if you had your motor line honed when it was built which may have changed the position of the crank ever so slightly.
If you suspect that there is something wrong with the scattershield, call McLeod immediately as they would want to know about this.

Jeff, good point. I did have the block line honed. That could explain why the BH appears "low" . I went back and checked it again tonight, this time with the register ring installed. I had the same alignment issue. I also slowly rotated the ring in the BH with the dial indicator installed. I saw the indicator move .005 while doing this.

Jeff, how would I know if, in fact, there is a problem with this unit?

Bill-
I would call McLeod on Monday. Call 714-630-3668 between 10-12 or 1-3 PST. Red (the owner of Mcleod) answers the tech line between these hours. Expalin your situation to him and he will give you better direction - he will want to know if there is an issue with his parts. He will be able to answer any other questiuons you may have as well (pilot bushing, etc.) - have a pen and paper ready to take notes. He is sometimes hard to get ahold of so keep dialing - it will be worth it.
My bet is that it is a line honing issue, the tool you are using, or operator error (no offense).
I hope this helps.

Bellhousings and engines were a matched set from the factory. The factory lined bored the transmission locating hole through the crankshaft mains. This is why most all factory manual transmission vehicles shift smooth from new.

But, if you take my 621 bellhousing from my engine and put it on your engine it will NOT be a perfect match.........close, but NOT perfect.

Yes, if you line bore your crankshaft the bellhousing alignment will change.

All blowproof bellhousings must be dial indicated, even McLoed's pretty machined one! Specs we use are +/- .005" or .010" total for concentricity and +/- .001" or .002" total for parallelism.

Our simple test for alignment or clutch adjustment problems is:

1.) Drive your vehicle for about a 10 mile ride to get her up to operating temperature.
2.) Shift the transmission into neutral and apply your parking brake.
3.) Idle your vehicle for about 10 seconds
4.) Depress clutch pedal to the floor and after 5 seconds shift your transmission into reverse.
5.) If you have a reverse gear crunch, you have a problem!
6.) If your clutch is engaging 2" off the floor......you most likely have an alignment problem.

Regards, Jody

The McLeod bellhousing come pre-dialed in from the factory - I have personally seen their equipment that checks for correct alignment before they apply the SFI sticker showing the readings. After that they ship them out. It is possible that you measured slighly wrong or you rdial indicator is not 100% accuarte.
McLeod builds some nice stuff. It is impossible however to ensure that a given part, a bellhousing for example will fit perfectly on every engine out there. There are too many variables that affect bellhousing alignment that have taken place over the last 50 years of building the same design small block Chevy to think otherwise. No bellhousing is going to fit perfect on evry engine, I'm sure his measurement are probably close, otherwise they wouldn't bother selling offset bellhousing dowels... :clonk:

I have installed .007 offset dowels to bring it w/in specification. I have not checked for parallel. Hopefully if any adjustment is needed I can use starter shims since that is all I have.