63 push rod info 327/340

[Edward J.]

Are the small block push rods all the same for the hyd. and solid lifter engines. thats Ed

[Joe L.]

Re: 63 push rod info 327/340

Are the small block push rods all the same for the hyd. and solid lifter engines. thats Ed

Edward-----

Yes. One very slight caveat, though, which is basically irrelevant as far as 1963 is concerned: Some early small block pushrods did not have hardened stems. So, if these pushrods are used in engines with hardened guide plates (which NO original C2 small block ever had), they will quickly fail. Without guideplates, it makes no difference.

[Clem Z.]

Re: 63 push rod info 327/340

till they went to guided rocker arms all SBC push rods used hardened tubing because they were guided by the double "D" hole in the head.

[Joe L.]

Re: 63 push rod info 327/340

Are the small block push rods all the same for the hyd. and solid lifter engines. thats Ed

Edward------


One more caveat: For 1962-1963 only, the 250 hp and 300 hp may have used a different pushrod than 340 and 360 hp. The 250/300 hp pushrod was GM #3817616 and the 340/360 hp pushrod was GM #3796243. The 3817616 was discontinued from SERVICE in October, 1963 and replaced by the 3796243. So, what's the difference? I THINK the 3796243 has a hardened stem and the 3817616 does not.

[Joe L.]

Re: 63 push rod info 327/340

till they went to guided rocker arms all SBC push rods used hardened tubing because they were guided by the double "D" hole in the head.

clem------


I'm not so sure about this. In 1975 I purchased a set of GM small block pushrods. The pushrods were all in GM packages but there were 2 different part numbers in the 16 I purchased (unfortunately, I did not make note of the part numbers). I initially installed the set on stock heads without guideplates. I had no problems. After a few thousand miles I changed the heads to GM heads with guideplates. Several of the pushrods failed in less than 500 miles.

I think the reason is that the guide holes in the heads are not hardened so non-hardened pushrods do not wear much. However, with hardened guideplates, non-hardened pushrods wear like "wildfire".

[Edward J.]

Re: 63 push rod info 327/340

Joe, When I rebuilt the small block I did install screw in studs and guide plates, but I purchased the push rods and rockers from my local parts supplier and was' sure if the rods had harden tips. I will have to dig up the slip and get the part no. and check. thanks Joe

[Clem Z.]

Re: 63 push rod info 327/340

Edward------


One more caveat: For 1962-1963 only, the 250 hp and 300 hp may have used a different pushrod than 340 and 360 hp. The 250/300 hp pushrod was GM #3817616 and the 340/360 hp pushrod was GM #3796243. The 3817616 was discontinued from SERVICE in October, 1963 and replaced by the 3796243. So, what's the difference? I THINK the 3796243 has a hardened stem and the 3817616 does not.

i would guess the hyd ones did not have the hardened insert in the tip and both ends were just formed. even the ones with a hardened insert had the lifter end just formed so GM marked the hardened end with a blue stripe so you would install them the right way up. i never saw a SBC push rod that was not file hard on the tubing.

[Joe L.]

Re: 63 push rod info 327/340

Joe, When I rebuilt the small block I did install screw in studs and guide plates, but I purchased the push rods and rockers from my local parts supplier and was' sure if the rods had harden tips. I will have to dig up the slip and get the part no. and check. thanks Joe

Edward------

Not hardened TIPS (I think they are all hardened) but hardened STEMS. You can check the pushrods you have by running a file over the stems. If the file won't cut the stem, you have hardened stems.

[Joe L.]

Re: 63 push rod info 327/340

I would be very interested if folks could check original pushrods they might have lying around to see if the stems are hardened, or not. All you need to do is to run a file across the stem. If the file "cuts metal" the stems are not hardened. If the file glides across without cutting, the stems are hardened. Basically, there were 4 pushrods used over the 1955-82 period.

1955-----------------------GM #3703924

1956-61--------------------GM #3837152 (yes, this is the original part number)

1962-63 (250/300 HP)-------GM #3817616

1962-63 (340/360 HP)
All 1964-82-----------------GM #3796243 (we know this one has hardened stems)

If you have some pushrods lying around that you are reasonably sure came from one of the above, it will just take a moment for you to check. Thanks

(I'M GOING TO START A NEW THREAD WITH THIS REQUEST, TOO)

[Joe L.]

Re: 63 push rod info 327/340

By the way, if one wants a really good GM SERVICE pushrod (also used in 84-86 PRODUCTION) use GM #14095256. This is a very high quality, welded-ball type pushrod. Welded ball construction provides a perfectly round tip with "270 degree" capability. This pushrod has a hardened stem and will work for any 55-86 small block with flat tappet hydraulic or solid lifters. The only problem is they cost about 17 bucks each, GM list.

[Duke W.]

Re: 63 push rod info 327/340

clem------


I'm not so sure about this. In 1975 I purchased a set of GM small block pushrods. The pushrods were all in GM packages but there were 2 different part numbers in the 16 I purchased (unfortunately, I did not make note of the part numbers). I initially installed the set on stock heads without guideplates. I had no problems. After a few thousand miles I changed the heads to GM heads with guideplates. Several of the pushrods failed in less than 500 miles.

I think the reason is that the guide holes in the heads are not hardened so non-hardened pushrods do not wear much. However, with hardened guideplates, non-hardened pushrods wear like "wildfire".

If you install guideplates, isn't it a good idea to open up the "D" holes in the heads? Otherwise the pushrod might be guided in two places, which can cause wear, even with minor interference.

Duke

[Joe L.]

Re: 63 push rod info 327/340

If you install guideplates, isn't it a good idea to open up the "D" holes in the heads? Otherwise the pushrod might be guided in two places, which can cause wear, even with minor interference.

Duke

Duke-----

Yes, it is. However, on heads which are supplied with guideplates (such as the ones I used), this is "pre-accomplished".

[Clem Z.]

Re: 63 push rod info 327/340

I would be very interested if folks could check original pushrods they might have lying around to see if the stems are hardened, or not. All you need to do is to run a file across the stem. If the file "cuts metal" the stems are not hardened. If the file glides across without cutting, the stems are hardened. Basically, there were 4 pushrods used over the 1955-82 period.

1955-----------------------GM #3703924

1956-61--------------------GM #3837152 (yes, this is the original part number)

1962-63 (250/300 HP)-------GM #3817616

1962-63 (340/360 HP)
All 1964-82-----------------GM #3796243 (we know this one has hardened stems)

If you have some pushrods lying around that you are reasonably sure came from one of the above, it will just take a moment for you to check. Thanks

(I'M GOING TO START A NEW THREAD WITH THIS REQUEST, TOO)

joe i am surprised you do not have them in your stash (not for sale of course)

[Joe L.]

Re: 63 push rod info 327/340

joe i am surprised you do not have them in your stash (not for sale of course)

clem------

I've got the 3796243 but I don't have the others YET.

[Bill M.]

Re: 63 push rod info 327/340

i would guess the hyd ones did not have the hardened insert in the tip and both ends were just formed. even the ones with a hardened insert had the lifter end just formed so GM marked the hardened end with a blue stripe so you would install them the right way up.

These had the blue stripe to indicate "blue side up" when new. The pic shows the tip insert. The other end does not have a tip insert. Purchased over the counter in the early 60s for installation in a solid lifter 327.