BBC thumb rods - replace or not ?

nashville beth · Jan 21, 2011

I just bought an assembled rebuilt 454. It was kept outdoors and uncovered by a moron- thankfully I bought it before it was damaged.

I knew it was dirty; I could see bird feathers stuck to the cam

(it didn't have an intake installed).

So I have disassembled it and the rods have been identified as thumb rods- a little bit stronger than stock.

Here are my engine specs: 454 +.030, forged dome pistons(10-1), stock cast crank, hyd roller 218/228 @.050 with .525 lift, edelbrock heads.

I know I will never go over 6000 rpm with this motor and will probably buy a rev limiter to guarantee it doesn't pass 5800.

I would still like to have the stronger rods with 7/16 bolts.

If I change to stronger rods, would everything have to be re-balanced?

I'm thinking that externally balanced engines like the 454 are pretty forgiving.

Opinions?

pnugene · Jan 21, 2011

Beth, those rods are just fine for your application. New rod bolts (if not already installed) are a good investment. With the power your combo will generate at the rpm's you'll be running, that engine is bulletproof, assuming the previous owner had his machinist do a proper rebuild. That's the caveat when buying an already-built engine, you're rolling the dice with someone's work that can only be verified by tearing it down, then inspecting & measuring everything.

71454Chevelle · Jan 21, 2011

Beth,

I ran thumb rods with ARP bolts in my last 454 combo for 20 years using heavy TRW forged pistons and seeing 6500 rpm's on a regular basis and had zero problems.

As Randy stated a good set of ARP rod bolts would be a good investment. :yes:

69 Post Sedan · Jan 21, 2011

Beth, I am also running the good truck rods but with new ARP bolts with my 402 BBC. Your combo, as the others said, will be fine. :yes:

Kurt :thumbsup:

nashville beth · Jan 21, 2011

Thanks Guys, I feel a lot better about this. The rod bolts are brand new; not sure if I can tell if they're ARP or not.
I will weigh each assembled piston/rod and see if they are the same, if not I'll have it rebalanced.
Appreciate the input ! :beers:

BBC thumb rods - replace or not ?

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