R the 5.3 LM heads casting 862 gen III a good upgrade for a ls1? If so will they fit right on or will i have to buy any special parts?

 

They are a good upgrade, but you'll gain more power with a camshaft + no heads rather than heads + no camshaft.

They fit "right on."

Stick a nice camshaft like the Futral Motorsports F13 in there while you're at it

You've done all of the bolt-ons first, right? If not, you'll need to such as longtube headers, catback, lid/CAI, etc.

Mike

 

If i did the heads, what would be the gain, i just got a set of remanufacture heads with everything for $150 is that a good deal.

 

i like my 5.3 heads with my cam, not bad for a budget, but i wish i held off and saved for trick flows or afr's

 

Unported and stock valves?

Maybe about 10-15 horsepower tops due to increased compression. Replacing stock heads with more stock heads and spending multiple hours of labor?

Just get a camshaft and gain 60-80 horsepower instead.

Mike

 

What is the best cam to use with these 5.3 heads?

 

Depends on what it's used for:

Daily-Driver = Futral Motorsports F-13 or F-14
Weekend/Track car = Futral Motorsports F-15

6-speed cars will benefit from a 4.10 gear
Autos will benefit from a 3.73 gear and a 3600 stall (Daily driver) or a 4200+ stall (weekend car)

Mike

 

As far as hp gain what would be my gain with the futral motosports f-13 and the 5.3 lm7 heads

 

Over 100 crank horsepower... even more if you top it off with a FAST 90/90 setup

Mike