Hey guys, 1st post in a very long time...

I'm helping a buddy out and trying to maximize his combo. It's been awhile since I've dove deep into combos... L77 (Gen4 6.0 w/ Rec ports)/4L80 (3,200-3,400 converter) going in a Buick Riviera. Max rpm will probably be 6,800-7k. ⚠️-Looking to bump compression. Was thinking a .040" gasket and cutting 3ish CC off heads (.025"). That'll obviously bump static up and bring the squish down a touch for KR resistance at the same time. Also wana play nice with P:V clearance as well. ⚠️-Cam selection. It's a heavy boat, and he's not big on driving it super hard. Looking to optimize TQ as much as possible before giving it up to peak HP. I initially was thinking BTR stage 2 V2 LS3.. but after alot of digging around seems guys aren't the happiest with it? I know LS3 heads generally like large splits but that doesn't always apply when u start getting heavy with the vehicle. My initial quick and dirty spec would be something like 228/234-6 113+2. Any body have any suggestions on cam choice or compression thoughts?

Thanks all!

 

That cam will be too soggy off idle for a barge like a Rivie. It needs a truck/RV/towing cam to haul its massive bulk around

 

This was my initial thought as well. Was leaning to a Truck Norris type deal. But it leaves WAY too much on the table for power. That's where the 3,200 or 3,400 converter comes into play. Im also considering the spin monster cam with a slight adjustment 230/234 114, no advance.

 

You need a turbo setup. You want big power all the way up and down and an NA will not do that. What actual power level are you going for?

 

Frick, you really should get your friend to set more reasonable expectations. Pending on the year, that car is 4100 to 4300 lbs. Rear end ratio can’t stay stock with that trans. Rear end should be like 3.73. That way OD is equal to 2.79. That high a stall also leaves you a narrow rpm band. More the 2500 to 3000. Headers are a must. Last the cam, a bit more than the truck Norris. I’d aim for 215 to 217 intake, 225 exhaust lift in the .553” to .600” lift. If this was an older light F-body your original combo would work. If he has the bucks to go turbo that does make the power easier. You would still want more gear and less converter to take advantage.

 

What expectation was set in the 1st post?

-the car will be right at 4,000lbs when the nialhead comes out.
-gears are currently 3.07... 3.55 will go in whe the rear is done. (2,300rpm cruise @ 75mph with 4L80 and 29" tire)
-it's getting 2800-3200 (most places give you a range of stall) converter, tight for the street.
-he bought bought a V2 stage 2 LS3 cam.
-gonna run LS2 head gaskets, so the quench idea is out. Just gonna knock .025" off the heads to get some compression in it. Holley and flex stuff have neen ordered for the swap.
-the swap will dictate what headers he can run within packaging constraints. Longtubes are always preferred, of course.

 

Ok now you mention gears and a tighter converter. Right direction .The cams not far off. He already has it. Lucky the old frames are wide. So fitting the headers won’t be bad.

 

I’d be tempted to run a good Cathedral head on it.

 

i ran almost this exact setup when i first put my 6.0 together except i had 24x block and crank and put the gen 4 rods and flat top pistons in it

my 823 heads were shaved .030" and i ran the cometic .041" mls gasket, when i first put it together i had an LS1 cam left over from another motor that i stuck in it which was an old comp grind and the specs on it were 228/236 .598"/.601" 112LSA, i did not have to flycut the pistons for PTV but always always always check when you start decking heads etc

it ran 7.1 @97mph 1/8 shifting around 6800 in my 3600lb raceweight monte carlo with a 3.80 gear and 26" tire so i think your initial quick and dirty spec is pretty close to where you want to be depending on the gearing hes running

EDIT: just saw in a reply that hes running 3.55 with 29" tire which is pretty tall gearing, i would go with less camshaft then in that case