HELP~Need info on 243 heads off of an 07' 5.3L Truck
11-02-2013, 11:17 AM
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HELP~Need info on 243 heads off of an 07' 5.3L Truck Are they the same as say the 243's off an LS2? I know the 243's that came on the LS6 had the hollow intake and sodium filled exhaust valves, but are the heads the same on all 3 versions I mentioned? I am asking because I am planning to install them on my 97' LS1 Corvette and am curious if the 243's off a 5.3L will bump up the compression on an LS1 like the 5.3L 706 heads do.
Or should I get the milled down some? If so how much?
Plans for my LS1 are for these 5.3L 243 heads, a good streetable cam, Pfadt Tri-Y headers, LS6 intake, and a Vararam & tune. Hoping for 425hp to 450hp at the wheels. Car is a 6 speed.
Or should I get the milled down some? If so how much?
Plans for my LS1 are for these 5.3L 243 heads, a good streetable cam, Pfadt Tri-Y headers, LS6 intake, and a Vararam & tune. Hoping for 425hp to 450hp at the wheels. Car is a 6 speed.
11-03-2013, 08:22 AM
#4
Chambers should be 64.45 cc which should raise your LS1 compression from
10.19 to 10.45. This is with no mill and GM mls head gaskets which are .054"
If you can't afford CNC porting, Advanced Inductions offers a quality valvejob
and spring kit to work with your cam choice. Milling them or using thinner
Cometic head gaskets can easily get you to 11+ compression however it
does minimize your piston to valve clearance which has to be considered.
Geoff at EPS or Martin at Tick could help you out with a proven cam combo.
10.19 to 10.45. This is with no mill and GM mls head gaskets which are .054"
If you can't afford CNC porting, Advanced Inductions offers a quality valvejob
and spring kit to work with your cam choice. Milling them or using thinner
Cometic head gaskets can easily get you to 11+ compression however it
does minimize your piston to valve clearance which has to be considered.
Geoff at EPS or Martin at Tick could help you out with a proven cam combo.
11-03-2013, 10:47 AM
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What I'm considering doing is just cleaning them up myself. Removing the rocker stud bumps in the heads, smoothing the guide bosses, blending the exhaust ports to match the gaskets, and just removing and polishing up the casting texture throughout. I wouldn't be removing very much material, basically just smoothing everything out. Should be easy enough to keep it all uniform that way. I have a two sets of 5.3L heads for a 5.3L I'm putting into my hotrod. I had planned on doing a lot more material removal on those but those heads are easy to come by if I screw up.
These 243's only have 14K on them. You think a valve job is even needed? I was thinking just clean them up like mentioned, new springs and retainers to match a new cam, new gaskets and I will be good to go.
Should I pick up the lifters, trays, pushrods, and rockers from the guy also? Or use what's in my LS1. My LS1 has 54K miles.
These 243's only have 14K on them. You think a valve job is even needed? I was thinking just clean them up like mentioned, new springs and retainers to match a new cam, new gaskets and I will be good to go.
Should I pick up the lifters, trays, pushrods, and rockers from the guy also? Or use what's in my LS1. My LS1 has 54K miles.
11-03-2013, 04:27 PM
#6
What I'm considering doing is just cleaning them up myself. Removing the rocker stud bumps in the heads, smoothing the guide bosses, blending the exhaust ports to match the gaskets, and just removing and polishing up the casting texture throughout. I wouldn't be removing very much material, basically just smoothing everything out. Should be easy enough to keep it all uniform that way. I have a two sets of 5.3L heads for a 5.3L I'm putting into my hotrod. I had planned on doing a lot more material removal on those but those heads are easy to come by if I screw up.
These 243's only have 14K on them. You think a valve job is even needed? I was thinking just clean them up like mentioned, new springs and retainers to match a new cam, new gaskets and I will be good to go.
Should I pick up the lifters, trays, pushrods, and rockers from the guy also? Or use what's in my LS1. My LS1 has 54K miles.
These 243's only have 14K on them. You think a valve job is even needed? I was thinking just clean them up like mentioned, new springs and retainers to match a new cam, new gaskets and I will be good to go.
Should I pick up the lifters, trays, pushrods, and rockers from the guy also? Or use what's in my LS1. My LS1 has 54K miles.
lapped in some hollow LS6 valves to my 15,700 mile valve seats. I know I
left a good 6-8 cfm of flow on the table but mine ended up flowing 246.5/200
So to answer your question NO not needed but strongly recommended. I also
left the intake runner rough. If you cartridge roll it use rough 80 grit as too
smooth creates boundary layer dropout and the port will stall bigtime.
