SBC tall deck rod length option

Dragsinger · 08-22-2019, 08:29 AM

I have a decision to make and am requestion experienced help.

I have a Brodix aluminum small block with 9.30 deck height. [4.125 bore x 3.80] the same short block has a 6.250 rod and a piston with 1.150 compression height. This is complete, balanced, running assembly, operating without problems but it is a high RPM, high maintenance package

I am removing the radical 11-degree heads and sheet metal intake and replace them with a nice set of fully worked Brodix dragon slayer heads and fully worked Super Victor II intake. [the 11-degree parts are all for sale and the setup is too radical for my usage]

I will be buying a shelf 23-degree piston with the pin relocated, several piston manufactures offer relocating a self stock pin for a small cost.

I expect this engine to make around 720 horse with an operating range between 6200 - 7800 RPM. It will be in a 2900 pound door car with an expected 5.90 1/8 ET. It will be Methanol fuel with carb.

Now to the question, keep the 6.250 rods or replace them with 6.0 rods? I will need to buy pistons either way and of course, if the 6.250 rods will perform as I want, it will save the cost of rods.

SSDiv6 · 08-22-2019, 11:34 AM

Larry,
I would go with the 6.25" rod length.
The engine will have a better rod ratio for the cylinder heads you pl lan to use.

08-22-2019, 08:29 AM	#1
Dragsinger VIP Member Join Date: Jul 2008 Location: Liberty City [East Texas] Posts: 1,759 Likes: 5 Liked 99 Times in 60 Posts	SBC tall deck rod length option I have a decision to make and am requestion experienced help. I have a Brodix aluminum small block with 9.30 deck height. [4.125 bore x 3.80] the same short block has a 6.250 rod and a piston with 1.150 compression height. This is complete, balanced, running assembly, operating without problems but it is a high RPM, high maintenance package I am removing the radical 11-degree heads and sheet metal intake and replace them with a nice set of fully worked Brodix dragon slayer heads and fully worked Super Victor II intake. [the 11-degree parts are all for sale and the setup is too radical for my usage] I will be buying a shelf 23-degree piston with the pin relocated, several piston manufactures offer relocating a self stock pin for a small cost. I expect this engine to make around 720 horse with an operating range between 6200 - 7800 RPM. It will be in a 2900 pound door car with an expected 5.90 1/8 ET. It will be Methanol fuel with carb. Now to the question, keep the 6.250 rods or replace them with 6.0 rods? I will need to buy pistons either way and of course, if the 6.250 rods will perform as I want, it will save the cost of rods. __________________ Larry Woodfin 471W

08-22-2019, 11:34 AM	#2
SSDiv6 VIP Member Join Date: Feb 2003 Location: Glendale, Arizona Posts: 2,991 Likes: 693 Liked 1,457 Times in 543 Posts	Re: SBC tall deck rod length option Larry, I would go with the 6.25" rod length. The engine will have a better rod ratio for the cylinder heads you pl lan to use.