Some of you may know I am building a 555 for my Vette. I am still looking for a block. I know of a guy selling a new CNC, splayed, studded billet cap, Gen 6, Bowtie block. Good for 4.6 x 4.6 in a 9.8 deck.

Anybody heard of or know of any reason not to get this block if the price is right ?

John

John,
Got two Bow Tie blocks I am doing right now. One is the splayed cap for a 540 & the other is the Aluminium GMPP small block for a 310 Trans Am deal
Both very nice, excellent sizing, lifter bore indexing etc.
I Just finished setting up the small block for roller cam bearings, .904 lifters etc. & when I put the fixture on to do them I checked the indexing before boring just for giggles.
My checking plug started into all the bores & went all the way in on 5 or six of them.
Just for reference I have had stock blocks that were so far off I couldn't clean the hole going from standard .842 to .875 :eek:

Just my opinion but what I have seen they are very nice pieces ;)
Every bit as nice as the Dart.

BTW, when you get ready for your lifters email me.

Thanks Wolfplace, I will keep you in mind regarding the lifters. I may go to a bigger lifters on this motor, .875 or even .904 if that is doable

John,
If the lifter bores are where they belong which with the small block bow tie stuff & the one rat I happened to check has been excellent there is no real reason I know of to go to .875 with a roller as the roller is the same size as the .842.
It is .750 for both.
The .904 roller is .810 & the reason in this case is my customer is upping the rpm of the engine from about 8600 to about 9400 & wants to keep the roller speed down to what he considers "acceptable".

Also,
As I don't do a lot of rats so I don't know if the gen 6 & 4 stuff is interchangable regarding heads.
My understanding is the gen 5 is the only problem one but someone else may wany to comment ;)

Thanks for the help Mike. As far as I know the Gen 4 and 6 stuff is fully interchangeable, except the main seal.