[jwhit]

started painting block before building last night and noticed bolt holes dont match the motor in car this is a newer 76 block and my car is 68 bird
does anybody here have diminsions on old block verses new block so i could
make adapters ?

[AG]

I think starting in 1976 they eliminated two extra motor mount holes that would have allowed installation in your '68.

[misterp266]

Butler sells adapters as do others.https://butlerperformance.com/i-2445...tegory:1393557

[25stevem]

Block side shot.

[Tom Vaught]

Know little about 1976 blocks except that the 455 engine was gone in 1977 and
the 1976 block is supposedly not very strong.

If Pontiac Dude was still posting he could tell you the whole skinny.

Tom V.

[25stevem]

Here’s all the bolts holes needed to have it go into any body and any year.

[redbird68]

I've used the block adapters, they work fine.
Not sure where i bought them, might have been yearone or classic ind.

[jwhit]

Originally Posted by 25stevem

Here’s all the bolts holes needed to have it go into any body and any year.

would you get measurements off for me

[25stevem]

I can't, that motor in my picture is in a car right now.

That adapter from Butler is what you need!

[johnta1]

This was from HPP magazine (I think):

We used a 455 short-block to measure the engine mount holes to make the steel motor-mount plates. Two 7/16-inch bolts were placed in the mount holes on the drivers side, and a 6-inch caliper was used to measure the center-to-center differences between them. Steve determined the measurement from number one to number two (left to right) was 3.060 inches. Number two to three was 3.650 inches, and three to four was 1.452 inches. Then using a 14-inch caliper, the outside bolt holes were found to be 8.610 inches apart. (If you dont have calipers, you can make a cardboard template and transfer the measurements.)

#1 and 4 are the late block mount holes. (don't need the #3 hole)

#2 and 5 should be the early motor mount holes.


I have never double-checked these, so take it with a grain of salt.

There was a thread (or more) on this conversion also on PY.

[jwhit]

Originally Posted by johnta1

This was from HPP magazine (I think):







#1 and 4 are the late block mount holes. (don't need the #3 hole)

#2 and 5 should be the early motor mount holes.


I have never double-checked these, so take it with a grain of salt.

There was a thread (or more) on this conversion also on PY.

thanks for the help

[jwhit]

here is sizes that worked the post below had it a little off

[johnta1]

Looks like the article may have switched a couple digits?
(8.61 instead of 8.16?)

The articles measurement from 2-3 and 3-4 were unnecessary for your needs. Too bad they didn't provide the inline holes like your pic.

EDIT: Looking at the block pic I posted, it appears the article also had the bolt holes numbered differently to what they measured in the article.
Their measurements are roughly the same as your pic (except 8.16" instead of 8.61 in article)

Their hole numbers should be 2 to 4 (3.65") and 4 to 5 (1.45")

Glad you found that pic.

[Singleton]

On your block you have one of the bosses necessary to drill and tap for the motor mount, (red arrow). Red circle is where the forward mount hole would be, but no boss there. If it were me I’d tap that rear bolt hole and use it in conjunction with the adapter strap for extra strength.

[johnta1]

Posting this as correction (for posterity):

We used a 455 short-block to measure the engine mount holes to make the steel motor-mount plates. Two 7/16-inch bolts were placed in the mount holes on the drivers side, and a 6-inch caliper was used to measure the center-to-center differences between them. Steve determined the measurement from number one to number two (left to right) was 3.060 inches. Number two to four was 3.650 inches, and four to five was 1.452 inches. Then using a 14-inch caliper, the outside bolt holes were found to be 8.16 inches apart. (If you dont have calipers, you can make a cardboard template and transfer the measurements.)

BTW, in my notes I had that someone on PY said the 2 to 5 measurement was 5.115". (OP's pic has 5.1")

[jwhit]

Originally Posted by johnta1

Posting this as correction (for posterity):




BTW, in my notes I had that someone on PY said the 2 to 5 measurement was 5.115". (OP's pic has 5.1")

wasnt trying to call out any one or offend i was just posting size that fits my block in case anybody elese needed the pattern
i drew this up in cad and laser cut and fits perfect i did drill and tap the 1 boss on block instead of grinding it off

[johnta1]

No offense taken. My info wasn't clear and trying to correct it.
Yours is a good pic of the holes/measurement.

[Schurkey]

Am I the only one here who gets puckered looking at those core plugs? They look like they were installed by beating a punch against the center of the plug, instead of being pressed on the outer rim.

[Tom Vaught]

Unless someone showed the installer how to do the job correctly, this is FAR more common than most think, on engine builds.

Tom V.

[jwhit]

Originally Posted by Schurkey

Am I the only one here who gets puckered looking at those core plugs? They look like they were installed by beating a punch against the center of the plug, instead of being pressed on the outer rim.

well thats they way these were made i knocked them in using large socket that just fit to inside on plug