383 Block question

[Darren]

Hey guys, im looking at a 68 383 block (block only)to potentially build a engine in the future. Is there any difference between these blocks in 68?
Not sure if they made a HP or something along those lines..
Thanks in advance for any info.

 

[GTX JOHN]

There are 68 HP 383 blocks.

I know because I have some.

The only difference that I am aware of is the have
a different HP Cam and Valvesprings.

Absolutely NO difference in the block = I have several different 383
blocks sitting next to each other in the shop and I have compared them
closely.

Also NO difference in any of the block 62 and up.

 

[Darren]

Thank you John. Good to know.

 

[RustyRatRod]

I was under the impression that the HP engines had higher compression because of a taller compression height on the pistons. But of course, that had no effect on the block.

 

[HemiSSDart]

The A-Body 383 blocks have a motor mount boss that is shaved off, so they don't work on any other body style...

 

[GTX JOHN]

I was under the impression that the HP engines had higher compression because of a taller compression height on the pistons. But of course, that had no effect on the block.

All the four-barrel engines as I recall back then had the same flat top
pistons and rated around 10 to 1 compression or so.

The two-barrel engines were low compression (more like 9 to I think) and
I seem to recall some of the mid late 60s even had a dished pistons.

I am not a 383 expert but that is what I seem to recall.

 

[BSB67]

Hey guys, im looking at a 68 383 block (block only)to potentially build a engine in the future. Is there any difference between these blocks in 68?
Not sure if they made a HP or something along those lines..
Thanks in advance for any info.

Yes, they are the same, except as mentioned in #5 above.

 

[Dana67Dart]

The A-Body 383 blocks have a motor mount boss that is shaved off, so they don't work on any other body style...

Does the shaved off boss need to be shaved off to fit an A body k member? And if so which one is it?

 

[Professor Fate]

The A-Body 383 blocks have a motor mount boss that is shaved off, so they don't work on any other body style...

And they also have an extra tapped boss for the motor mount that is not present (or may be present but is not tapped) on standard blocks.

 

[RustyRatRod]

All the four-barrel engines as I recall back then had the same flat top
pistons and rated around 10 to 1 compression or so.

The two-barrel engines were low compression (more like 9 to I think) and
I seem to recall some of the mid late 60s even had a dished pistons.

I am not a 383 expert but that is what I seem to recall.

That certainly makes sense, John. Thank you!

 

[RustyRatRod]

Does the shaved off boss need to be shaved off to fit an A body k member? And if so which one is it?

See if this helps. I don't see any ears shaved off at all.

 

[RustyRatRod]

In this thread, you can see there is an ear shaved off. But yet in the picture I posted, it's still there.

S

Thread 'a Body 383 Block pics'

May 12, 2024

Greetings All, Can anyone post some pics of a factory altered A body 383 block that illustrates which casting ears they removed/ I had them at one time but now I need em and I cant find em. Thanks

• scudapie
• Replies: 5
• Forum: Big Block A body Tech

 

[HemiSSDart]

In this thread, you can see there is an ear shaved off. But yet in the picture I posted, it's still there.

S

Thread 'a Body 383 Block pics'

May 12, 2024

Greetings All, Can anyone post some pics of a factory altered A body 383 block that illustrates which casting ears they removed/ I had them at one time but now I need em and I cant find em. Thanks

• scudapie
• Replies: 5
• Forum: Big Block A body Tech

That is because it is not a factory A-Body block. I put a 69 Roadrunner 383 block in my 69 GTS and did not shave the motor mount boss, it works but is damn close to the sector like the picture you showed...

 

[RustyRatRod]

That is because it is not a factory A-Body block. I put a 69 Roadrunner 383 block in my 69 GTS and did not shave the motor mount boss, it works but is damn close to the sector like the picture you showed...

I suspected that. Thanks for the confirmation!