Settle a SBC arguement?

A guy I work with was arguing with another guy about the number of bolts holding a small block Chevy engine and tranny together.

He's insisting that some used 7 bolts, with the 7th being located at the top center of the bell housing. He first claimed this was used in the '60's & '70's, but when I pointed out the bolt hole in the block is above the highest point on the bell housing, he started saying it must have been the earlier ones.

Anyone have pics of the back of an older Chevy engine, preferably with the factory tranny or bell housing bolted up? Can anyone point to any Chevy that used 7 bell housing bolts?

Thanks,

 

'58 block

'55-'62 scatter shield

 

well, he's right cuz i've seen a few bellhousings and blocks withe that friggin' hole but damned if i know what they were out of.
i'm guessing 1ton and up trucks,manual trans, obviously

 

Yep it sure did. Don't ask me when they stopped using it but it was there on the earlier SBCs

 

My 65 327 block has the tapped hole but the bellhousing im using (403)dont use it. I thought that hole was used for a bracket to hold the draft tube stuff ?

 

It's kind of funny to me. I can remember being surprised when I saw the non-drilled block for the first time.

 

the early sbc iron PG adapter had that hole used to bolt the adapter to the block....

 

The early chev did have a center bolt, my 59 Vette block had it. the 58-61 bellhousings were drilled for the center bolt do not know the last ones to use it.

 

Thanks for the replies and pics, that settles it as far as I'm concerned. I told him I knew where to find out for sure...

 

i have always heard if the top center hole is treaded its a 4bolt main..

 

Hmmmm...

'79 block, 2 bolt main, with the 7th hole tapped. I don't have a bolt in it because it interferes with the bottom of the firewall.

 

all you old guys with your useless information! i almost know everything you forgot, but forgot everything you know! it was seven DWARFS!!!!!!!

 

heh...that's a good one! 4 bolt main 265s, 283s, and 327s....

 

Thats an exciting prospect, traditional SBC, with 4 bolt mains. I can dream cant I?

 

You can own an early/trad 4 bolt block. Send me an early block and some 4 bolt main caps, I can make your dreams come true.

I never looked real close at the early blocks but on the later blocks the two bolt block has heavier webs so you can actually come up with a 4 bolt block that's stronger than the factory 4 bolt.

Anyway back to the topic:
Here's the real kicker, I can't vouch for everyone else but we used to leave the top bolt out said it wasn't necessary and took too much time to put it in. As if the time it took to put it in would make any difference in the whole rest of our lives.

 

I have a cast 67 Chev. truck bell housing in my car and it has the 7th hole.(in use)

 

Back in the old days I left lots of hard to get to bolts out. I also broke a lot of stuff. Now if it has a bolt when I take it apart, I put it back. I still break shit.

 

Got eny miniature donkeys for sale?

 

Remember that Johnny Cash song about working at the GM plant & collecting parts for 20 years.Then one night they decided to bolt it all together & thats when "they discovered all the holes were gone - but they made it fit with the help of a adapter kit". Now I have an idea about the mystery hole..................Gary 4T950 Chevy Guy

 

Dad worked at a Chevy/Olds dealer when the SBC was new. He has a 3' extension standing next to his tool box, purchased just to help get to that extra bolt. Probably made sense to put one there when Chev used bell housing mounts and the transmission just hung of the back.

 

The real reason GM stoped drill/tap etc was the bolt was not needed. The other reason less machine time one less bolt to purchase and less labor to install. It speed up assembly line time and one less bolt to buy. So the accounts were happy and it helped on the bottom line.. One last thing a lot of the later truck motors were drilled and taped. most were straight shift and had the 5 bolt transmission. Most were 0010 cast numbers and a lot of them were 4 bolt main but not all..I know its confusing but its big business calling the shots... Later Bobby..

 

"The other reason less machine time one less bolt to purchase and less labor to install. It speed up assembly line time and one less bolt to buy. So the accounts were happy and it helped on the bottom line.. "

Funny you should mention that. Once again back when Dad was a GM mechanic he said every single new car came off the truck 1 quart low on oil. Motor oil was about $.10/qt back then, but $.10 on half of all the cars sold in the US added up to a pretty good chunk of change for the General.

 

See my profile vehicle the 74 Suburban it has one don't need it as long as that heavy ass Muncie fit a 6 bolt bellhousing they didn't give a rats ass! LOL

 

Man you really need to pay attention to the dates on things you respond to. The person you are answering was from 2006 - 14 years ago - and he hasn't around since 2010 in any case.

 

All info is good info!

 

I thought all the small blocks and BIG blocks had 7 holes for the trans to bolt on...... Yes! This thread is over 14 years old.....

 

Old but very interesting- I never saw one before!

 

pulled a 350 out of a 80 c65 that used the 7th bolt.

didn't see the date either.

 

My thanks to @Randall Landfair for bringing this back to the top. I had always wondered about that 7th hole and was just ashamed to show my ignorance by asking.

 

Thank You torqued my bellhousing last night almost shit my pants when I saw that 7th hole finishing up the clutch job and getting ready to wiggle the heavy 3 speed Muncie into her!