block numbers

[joe68]

am i right in my thinking,that the only way to tell the 302 from the 350 block is in the bore? beside the casting on the crank.

[Blue Bowtie]

Originally Posted by silicon212

1976 = first year of 305

Oooh! silicon is usually right on the money - Let's see if we can trip him up on trivia...

Are you saying that the 305 did not exist (in a Chevy) in 1960-66?


BTW - The 302, 327, and 350 all have a 4.001" bore. The only way to differentiate is the stroke, or the resultant crank casting number. Since some builders assembled 302s with 2.45" spacer mains (or aftermarket medium journal cranks) even the mains sizes don't always follow suit. If you have a ruler graduated to at least ¼" resolution, you should be able to determine what you have. It is even easier if at least one of the pistons/rods is still installed. A 302 has a 3" stroke, a 327 has a 3¼" stroke, and a 350 has a 3½" stroke (3.48" actually, but your scale probably isn't graduated in hundredths). Besides, true 3.500" stroke cranks are commonly available, but I'm confusing you enough already.

[silicon212]

Originally Posted by Blue Bowtie

Oooh! silicon is usually right on the money - Let's see if we can trip him up on trivia...

Are you saying that the 305 did not exist (in a Chevy) in 1960-66?

Not as a V8, but it certainly existed as a V6 usually found in trucks such as GMC and the Apache... IIRC, it was a 6-cylinder version of the 409.

[joe68]

now you talking , that was a really good explaination for me.
very well put! i thanks you for clearing that up for me.
so if i set up a idicator off the block and onto the piston and crank motor
i will get exact stoke?

[joe68]

a v6 between 1960 and 1966? in a truck?

[jveik]

yeah and the 4.3 v-6 that was always in old s-10's is actually a 350 with two cylinders missing, i believe anyways.

also, wouldnt a 302 rev pretty damn high with that short stroke? i have heard stories of 283's revving up to 10000 but i dont buy it unless maybe they had a lot of mods, especially in the valvetrain.

[GreyGoose006]

10K may be a little high, but 8-9K is possible with light pistons in a 283.

[Blue Bowtie]

Originally Posted by joe68

now you talking , that was a really good explaination for me.
very well put! i thanks you for clearing that up for me.
so if i set up a idicator off the block and onto the piston and crank motor
i will get exact stoke?

Yes. But you really don't even need an indicator. If a head is off (or oil pan is off) and you bottom a piston, measure to the deck, then stroke the piston to its opposite end, you should have the stroke. Since there is a quarter-inch difference between cranks, a scale should show the stroke. If you have a 4" travel indicator, that would work, too, but it's overkill.

Yup - Couldn't fool silicon212. He picked up on the V-6 out right away. You can usually trip up some people asking about the "305" with that one. That engine family included the 305, 351, 379, 401, 432, and 478 V-6s, plus the 637 V-8, and the 702 V-12.

[seattletri]

joe68,

I was reading your following expertise test and found out that my block casting number match your test. I read further and found out I have a 302ci from a 1969 Camaro Z28. Where would I find the 'right front pad' number? I am new to muscle car code identification and just need some help. Mine is a 1968 Impala and was told I have the original 327 :-) Doesnt seem to be the case.

ok guys lets test your expertize

block cast number 3956618
cast in front of gm is the numbers 19
right front pad v0307hu

[silicon212]

Originally Posted by seattletri

joe68,

I was reading your following expertise test and found out that my block casting number match your test. I read further and found out I have a 302ci from a 1969 Camaro Z28. Where would I find the 'right front pad' number? I am new to muscle car code identification and just need some help. Mine is a 1968 Impala and was told I have the original 327 :-) Doesnt seem to be the case.

ok guys lets test your expertize

block cast number 3956618
cast in front of gm is the numbers 19
right front pad v0307hu

This is a pretty good necropost here ...

The "right front pad" is actually on the block, directly above the right water pump outlet (on the LEFT when looking at the front of the block head-on, the even numbered side). It's a machined extension of the cylinder deck, where information regarding the block is stamped (usually information pertaining to the assembly factory plus a part of the VIN, usually the last 8 digits of the VIN for a '69 through '80 vehicle).

A '68 will have a large journal block, whether it's a 327 or 350. The block identification would be the same on either (as above, usually these were 3970010 - alternatively, just 010 - blocks).

To determine whether your engine is a 327 or 350, you could measure the stroke or pull the pan off the block and check the crank casting #. I've given the relevant numbers above. The 327 uses a 3.25" stroke where the 350 uses a 3.48" stroke. A 302 would have a 3" stroke. All would use a 4" bore, and beginning in 1968, a common block.

[seattletri]

Thanks Silicon for the fast response. In this post thread, a 19 in front of GM then block code 3956618 is from a 1969 Camaro Z28? Here's what I have, without measuring the stroke, can you tell me the engine size?

block cast number 3956618
cast in front of gm is the numbers 19
right front pad v0422pa

Again, I am totally new to this engine decoding. I just purchased a 1968 Impala Convertible cloned SS327 and a 1968 Corvette Convertible with a 396 from a 1965 Corvettte. I didn't have a problem decoding the engine from the Vette. Thanks in advance.

[maxwedge]

See this link. http://www.nastyz28.com/sbchevy/sblock.php

[seattletri]

Thanks MaxWedge - I looked at the engine block suffix again and it's FA instead of PA. The NastyZ website confirmed it's a 1969 327. Thanks again.

[joe68]

sorry guys this was reposted somehow from a long time ago!
can't explain it! but anyway motor was done and in car and running, hope to finish this winter, thanks for all the help