396 375 H.P.

[Andrew Strauss]

What size connecting rod bolts were used in the 396/375H.P. engines? 3/8 or 7/16

Thanks in advance

[Warren F.]

Re: 396 375 H.P.

Andrew,

All had 3/8ths.

[John H.]

Re: 396 375 H.P.

I think you meant 425hp, unless you're doing a Camaro.

[Ken A.]

Re: 396 375 H.P.

If you use 3/8 buy a 100# bag of oil dry for it will surely self destruct!

[Clem Z.]

i build all my 396/427 drag race engines with .

3/8" rod bolts because a set of 8 rods weight about 1# less than a set of the 7/16" bolt rods. we turned these engines to 8000 RPMs without a rod bolt failure. we used after market bolts with preped stock rods and light weight pistons.

[Joe L.]

Re: i build all my 396/427 drag race engines with

clem, et al-----

The only big blocks that ever originally used 7/16" bolt rods were 1969 L-88/ZL-1, 70 LS-6 (Chevelle), and 71 LS-6 (Corvette). Late 1968 L-88 may also have used rods with the 7/16" bolt rods. All other big blocks originally used 3/8" bolt rods.

[William C.]

Re: i build all my 396/427 drag race engines with

Ditto on my Drag race engines, took aftermarket 3/8 rod bolts to 7200 repeatedly without failures.

[Ken A.]

Re: i build all my 396/427 drag race engines with

Big block drag race engines are built for 9000-10,000 RPM today & use 7/16 bolts from ARP & others. No one I knew of ever used stock GM 3/8 rod bolts on a hi-po engine app. All the race engines built by GM in the early 70's used the boron 7/16 bolt. Of course you can use whatever you wish, it's your engine but I doubt a pound made much difference considering the weight of the crank & rods.

[Clem Z.]

Re: i build all my 396/427 drag race engines with

corvette engines build for endurance road racing used 7/16" rod bolts but street and drag race engines with the 3.76 stroke stand up using aftermarket 3/8" bolts. when you get into longer stroke you need the bigger bolts even in drag racing. rods are designed by using the HP that will developed per cylinder in the engine.