How can I tell the difference between the regular 3/8 rods and the truck 3/8 rods. i searched but couldnt find any info on how to tell the difference.

According to my engine code my 454 came out of a 77 truck, so Im assuming it has the truck rods. Are they stronger than the regular 3/8 rods.

Also, according to what I've learned so far my 3/8 rods should be OK at my mild power level of around 450 horsepower and my 5500-6000 redline. But what if I put a 150-200 shot of nitrous? Will they handle that much with good rod bolts and being resized?

Thanks in advance smile.gif

454's are the same,car or truck, unless you find a 4 bolt main,2 bolt mains are tough too. I think you'll be fine with resizing the rods and ARP bolts,good pistons and nitrous.

Bob there is a difference in the rods, between older BBC pass car motors and later motors used mostly in trucks.

The "truck" rods are beefier on the bottom end, and more desirable, although either will work OK.

Truck rods resized with ARP Wavelocs, will go to 6500 no problem. Even with a 200 shot.

http://mediaservice.photoisland.com/auction/Jul/20047258833574905352778.jpg

rod on the left is a "truck" rod

Looks like I got the regular 3/8 rods then :(

Anyone run a 150 or 200 shot on the regular 3/8 rods?

Just make sure you use ARP rod bolts...GM rods are forged, and according to what I've been told by folks here and elsewhere, will stand up just fine to 6,500 rpm.

Originally posted by transam77transam:
Looks like I got the regular 3/8 rods then :(

Anyone run a 150 or 200 shot on the regular 3/8 rods? =

You should not have a problem with the regular rods, there is very little difference in strength between the two & they are both extremely strong.
What kills rods is not HP within reason, it is RPM & piston weight.

Which brings up another subject,,, ads that rate rods for X amount of HP. :mad:
Complete advertising crap as you cannot rate a rod by HP without regard to RPM & piston weight.
The compressive loads on a rod are nothing compared to the tension loads when the rod changes direction on overlap when there is no load on the piston.
These loads increase with RPM, stroke & to a smaller degree shorter rods.
Of the three, RPM is the biggie

Almost all rod failures are from the rod being "pulled" apart or a bolt failure, not from being "pushed" on to hard.

The exceptions would be extremely heavily blown or nitrous usage like 2000+ HP stuff as an example.

Are truck rods comparable in strength to say a Scat I beam or H beam rod. If not what is the max horsepower they can handle , oops sorry Mike :rolleyes: , I mean rpm's. Can they be used w/ a 4.25 crank?
Mitch

Originally posted by hamrdown:
Are truck rods comparable in strength to say a Scat I beam or H beam rod. If not what is the max horsepower they can handle , oops sorry Mike :rolleyes: , I mean rpm's. Can they be used w/ a 4.25 crank?
Mitch =
The Scat's are 4340 & use a capscrew so they are going to be stronger both in material & design.

Don't have a clue what the max RPM is going to be before they make you unhappy but I'd venture to say it is up there pretty good. ;)

I ran L88 rods to well over 8000 with a 4" stroke years ago but am not recommending doing this on a regular basis as this is before anyone told me I "couldn't" do it :D
I would not do this today as there were a few problems that needed to be addressed to make it live.

In a 4.25" stroke I prefer to use a 6.385 rod as it makes balancing the engine much nicer.
With the stock rod, which by BTW is about 30-50 grams heavier than a Scat 6.385 H beam, balancing can get a little "challenging".
You will have about paid for a set of new rods before you are done.

To answer your question, I don't think you would have a problem with 6-6500 or so.

Thanks for the help guys. I figured they would be alright since my redline will probably be around 5500-6000 rpm. Just wanted to get some professional opinions to make sure. smile.gif

He, He!!

Somebody once said if your thumb fits in the indent, they are truck rods!!!

Good analogy imho...

pdq67

The 454 I have in the garage came from a 73 Suburban and it has the "passenger vehicle" rods? a suburban is not considered a truck? guess not :(

The rods called truck rods are from the tall deck truck blocks not std height blocks stuck in light duty trucks. If you have a set of truck rods use them they are better than the pass rods but you must rebalance they are heavier. I still have the two pieces of a 7/16s rod that saw 8400 too many times in a 4in stroke motor with two ton pistons.

Originally posted by Mike Feudo:
The rods called truck rods are from the tall deck truck blocks not std height blocks stuck in light duty trucks. If you have a set of truck rods use them they are better than the pass rods but you must rebalance they are heavier. I still have the two pieces of a 7/16s rod that saw 8400 too many times in a 4in stroke motor with two ton pistons. Incorrect,
they are not necessarily or exclusively from a "truck" engine, i.e. a 366 or 427.

Most later 70's-up 454's used in pickups, motorhomes, etc.. came with the "truck" rod.

It is just a method most BBC people use to describe the different rods and isn't meant to denote a 366/427 TRUCK motor rod. Many of those use the Pass rod. Depends on year more than anything.

Bob,
Your early 70's 454 may be before the time of the "truck" rods. Seems right around 73-74 is when they started being used. Most cores I've torn down are from the 73-early 80's era and have them.

Older 396's did not.

A stock rod can be used in a stroker but as Mike mentioned you are money ahead to buy some SCAT I-beam capscrew rods by the time you pay to have your stock ones reconditioned, ARP bolts, and the additional money for Mallory metal that the small counterweighted stroker crank would require.

I stand corrected. I really paid no attention to the later 454 internal parts I was just using the blocks. One thing though the very early 396s and even the L-72s had terrible rods that were up dated in 1967. If you think you have an early set look at a later set to make sure. I was told there actually was a recall on them but I didn't ever hear about it.

My '74/'75, 454 P/U core motor had them in it. Along with -781 heads with rotators.

pdq67

This weekend I dug up a spare rod that I had lying around, (it was damaged and replaced from a rebuild of about 15 years ago) and after looking at it in a little more detail, I discovered that the rods in my engine are truck rods. graemlins/hurray.gif

The question that I have is what is the material of these rods made out of? I know that they are forged, are they 4340? :confused:

Please let me know.