04 5.7 Truck motor what heads to get to upgrade?
I have a 2004 5.7 I have put about 50,000 miles on it, looking for new heads unsure of where and what to get. Not looking for a radical build. Street use and solo autocross only, maybe install a cam later.
In my opinion, heads are a good upgrade, but without a cam and other mods you really won’t see much gain from them. The stock heads flow really well from the factory, so if I was gonna spend the money on heads I’d do cam/heads at a minimum. There are several big vendors that do ported heads with great reviews, but they come at a price... modern muscle, inertia, high horse performance.
Second, what is your exhaust currently? Headers?
There is tons of info out there on putting 5.7 eagle heads or 6.1 heads on a early 5.7 to bump compression and get a more flow as cast from the factory. That would help save some $, but you won’t see as big of gains as you would with the same heads ported. Also, they both have larger intake ports which would require a intake swap due to a large port mismatch. Modern muscle has intake adapter plates (that I have tried and am not impressed with). The exhaust ports are also different shape, so new headers would be in wise as well in that situation.
My personal thought is that a basic 3 angle valve job has been proven time and time again to improve flow. Also, flow improvement from porting is mainly seen with work in the bowl. So finding a local builder that has a good reputation with head work and getting mild bowl porting, and a 3 or 4 angle valve job along with milling the heads a bit would be most beneficial to give you flow and a compression bump too. But truly, add a cam with the heads to see any real gains.
Joe
