should ls1 heads fit on a standard flowbench jig for SBC & BBC? meaning a std 4.0 in bore?

 

SBF will work.

Chris

 

small block ford? really? damn gm is strange

 

Yes, most shops are using the SBF BHJ plate to hone cylinders instead of buying the new LS1. The LS1 heads bolt directly on a SBF block and if you turn the intake around it will line up with spacer plates to take up the deck height difference.

Chris

 

thanks chris

 

so im taking the ford is a 3.90 bore?

 

it appears to be 4.002 i think?

 

The SBF has a bore spacing of 4.38", the LS1 has the same bore spacing as a SBC 4.40", so it will be off .020"-.040" from one hole to the next, if the head is centered, which will be hard since the dowels don't fit either.
And when we mocked up a SBF intake on it, it did not line up at all, no matter which way you turned it. The runners from the SBF to the LS1 run at completely different angles, the LS1 is more "compact" from end to end, the SBF is more "spread out" from end to end. See what I mean??

 

They will sorta fit but not give accurate numbers. If you plan on running a set of heads on a 3.90" bore then flow it on a 3.90" bore.

For example
our Stg 2.5 6.0L/LS6 intake program on a LS6 head with the stock 3.90" bore chamber flows 325 @.600" on a 4.00" bore and 320 on a 3.90" bore- only a loss of 5cfm

The 6.0L head with the same exact everything flows 324 @ .600" on the 4.00" bore but only 309 @ .600" on the 3.90"- a loss of 15 cfm

so you can see if you flow a head with a chamber that is bigger then the bore you flow it on then it is very ditrimental to the flow, so you may not get the full answer if you port and flow LS1 heads on a 4.00" bore fixture. Hope this helps. Brian

 

Thanks Brian