Were 7/16's rods used in truck 454's, or did they only use 3/8''? I'm just wondering because I was thinking my engine was a truck motor. I also ordered ARP bolts and oops! ordered 3/8s rod bolts, but my machinist says I have 7/16ths. The 7/16's are the more desireable right, at least for performance? Thanks...

As far as I know the 7/16s rods were only used in L-88s ZL-1s LS-6&7. Hundreds were sold over the counter but a stock truck motor should have 3/8s.

I think they were used in all of the high hp motors of the time,396,427, and 454. I`m almost positive that any motor that came stock with high compression and square port heads had 7/16 rods.

Truck or "thumb" rods... GOOD rods for the price when worked over and good aftermarket bolts are used, imho..

pdq67

This is true:
Mike Feudo
Tech Team


posted 01-13-2005 14:52
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As far as I know the 7/16s rods were only used in L-88s ZL-1s LS-6&7. Hundreds were sold over the counter but a stock truck motor should have 3/8s. This is not:
sschevellefan
Tech Team


posted 01-14-2005 00:43
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I think they were used in all of the high hp motors of the time,396,427, and 454. I`m almost positive that any motor that came stock with high compression and square port heads had 7/16 rods.

Originally posted by David_Bates:
This is true:
</font><blockquote>quote:</font><hr /> Mike Feudo
Tech Team


posted 01-13-2005 14:52
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As far as I know the 7/16s rods were only used in L-88s ZL-1s LS-6&7. Hundreds were sold over the counter but a stock truck motor should have 3/8s. This is not:
sschevellefan
Tech Team


posted 01-14-2005 00:43
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I think they were used in all of the high hp motors of the time,396,427, and 454. I`m almost positive that any motor that came stock with high compression and square port heads had 7/16 rods. </font>[/QUOTE]did`nt the 375hp 396 have 7/16 rods? What about the 425hp 427? I`m pretty sure all of the hi performance bbc had the 7/16 rods. If I`m wrong maybe you should explain why I`m wrong instead of saying what I posted "is not true". Kinda sounded like you called me a liar, but I know you did`nt, right?

Anthony,

How can I explain that your statement is wrong other than saying "1969 L88 and ZL1 427's and any LS6/LS7 454 got 7/16" rods. All other 396/402/427 BBC's to include 375/425/435HP got 3/8" bolts". The part number was 3856240 - 3/8" bolt, dimple and pressed pin. L88/ZL1 was 3969804 - 7/16" boron steel bolts, dimple and floating pins.

No, I didn't call you a liar. Just not 100% informed.

GM produced two versions of rods with 7/16" bolts.

14096151 was a pressed pin design, used in LS-6 and LS-7 engines. Bolts were 14096148, nuts were 3942410.

The other version, 3969804, was a floating pin used on L-88 and ZL-1 engines. Boron bolts 3969864 were magnaflux inspected, twelve point nuts were 340289. Great rods, but very expensive.

As Dave mentioned, all other engines used 3/8" bolts.

John

Originally posted by David_Bates:
Anthony,

How can I explain that your statement is wrong other than saying "1969 L88 and ZL1 427's and any LS6/LS7 454 got 7/16" rods. All other 396/402/427 BBC's to include 375/425/435HP got 3/8" bolts". The part number was 3856240 - 3/8" bolt, dimple and pressed pin. L88/ZL1 was 3969804 - 7/16" boron steel bolts, dimple and floating pins.

No, I didn't call you a liar. Just not 100% informed. It was just the way you put it, "true", "Not true". Maybe I just need to wake up a little more before reading posts so I`m not so grumpy. I always thought the hi peformance motors got the 7/16 rods and the lower hp and truck motors got the 3/8 rods. I guess I stand corrected.

Actually 68 L-88s had 7/16 rods. They were the first. The 67 L-88s had a full floating much better 3/8s rod but it still failed too often so the change in 68. The HP 502s use a 7/16 rod but I know nothing about it.

Taylor,
Any possibility that your engine was originally a marine engine ? A lot of the marine 454's have the 7/16 bolts in them, along with steel crankshafts.

I'm not too sure on its history actually. I bought it after my friend took it out of his '68 Camaro, which he knows little to no history on. From what I recall on the casting number, it's a 14015445. The reason I think it was from a truck is because of decoding the vin that was on it (though I don't have that on hand). It was a long time ago when I checked all that though, about a year before I had money to purchase it, so I'm not too sure. All I know is it has 7/16 rods and is a 4-bolt main. The engine turns out was a virgin block too. Got the complete engine for $600, accesories and all. Go me!

And did you know that Chevy made some sets of "rare as hens teeth" longer rods for the CanAM motors way back when..

I think they were like 6.40" or so long?? One of my old mag's/books has a part number for them but it would take me a while to dig it out...

pdq67

Those "long" rods were used with the aluminum CanAm 430 cu. in. block - 3.47" stroke and 4.44" Bore.

Those rods were also used in the Turbo-Marine 482-Offshore racing engines built by GM for Mercury Marine. They are just a touch longer than the 6.385 rods we're used to: 6.405.

The 4.25 stroke in a tall deck block, and 6.405 rods allow the use of ordinary 454 piston-pin-height pistons.

Wished they weren't so rare b/c I figure they would be dandy for us 496'ers..

pdq67