CLASS RACER FORUM - View Single Post - Best Engine for Class Rules below, not Drag Racing

Adger Smith · 08-22-2011, 08:38 AM

429/460 = #25

I like the 70 mod LS-6 BB or even the '69 427 425 hp BB
The conventional vortec BB might work, I have no experience with those BB heads, but if they are as good an upgrade as the SB Vortec it might work.
The later Vortec 8100 has cast heads and could be the ticket, but it's 4.25 bore and 4.37 stroke makes it go about 10 over the cu in limit. Not sure if the induction would work, either. Destroke?
If you like later mods then the LS truck engine w/ iron heads:

Casting Number 373
Head: 1999-2000 LQ4 6.0 Litre Truck
Material: Cast Iron
Part Number:
12561873
Combustion Chamber Volume: 71.06cc
Compression Ratio: 9.5:1
Intake Port Volume: 210cc
Exhaust Port Volume: 75cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches
There is a thread on one of the LS forums that says the iron head can be made just as good as the LS-4 head can. There is a nice 4 BBl intake avaliable for them,too. Put those iron heads on a block with a larger bore and stroke it a little.. Let it fly!!
What is the most common engine being used?

08-22-2011, 08:38 AM	#4
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: Best Engine for Class Rules below, not Drag Racing 429/460 = #25 I like the 70 mod LS-6 BB or even the '69 427 425 hp BB The conventional vortec BB might work, I have no experience with those BB heads, but if they are as good an upgrade as the SB Vortec it might work. The later Vortec 8100 has cast heads and could be the ticket, but it's 4.25 bore and 4.37 stroke makes it go about 10 over the cu in limit. Not sure if the induction would work, either. Destroke? If you like later mods then the LS truck engine w/ iron heads: Casting Number 373 Head: 1999-2000 LQ4 6.0 Litre Truck Material: Cast Iron Part Number: 12561873 Combustion Chamber Volume: 71.06cc Compression Ratio: 9.5:1 Intake Port Volume: 210cc Exhaust Port Volume: 75cc Intake Valve Diameter: 2.00 inches Exhaust Valve Diameter: 1.55 inches There is a thread on one of the LS forums that says the iron head can be made just as good as the LS-4 head can. There is a nice 4 BBl intake avaliable for them,too. Put those iron heads on a block with a larger bore and stroke it a little.. Let it fly!! What is the most common engine being used? __________________ Adger Smith (Former SS)