Vortec 454 Heads and Cam
#1
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From: Willows, California
I'm looking for a good set of heads and a cam for my Vortec 454 powered Silverado. I was just planning on just a K&N Intake, Hooker Headers with full exhaust, tuning, a shift kit and removing all of the emissions equipment but I have decided to throw on some heads and a cam too. So, what would you guys suggest?
#3
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From: Willows, California
It's a 1998 Engine/Trans that I'm swapping into my 1989 Silverado. I'm kinda wanting some aluminum heads that will give me some more power and work with whatever cam you guys suggest. I'm putting in an after market pump and regulator, if I need injectors I will get some.
#7
It's a 1998 Engine/Trans that I'm swapping into my 1989 Silverado. I'm kinda wanting some aluminum heads that will give me some more power and work with whatever cam you guys suggest. I'm putting in an after market pump and regulator, if I need injectors I will get some.
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#9
There are plenty of choices for oval-port aluminum heads for the L29. GM Performance Parts sells aluminum 110cc heads, part number 12363390. They have dual valve springs and will support more RPM with a different cam. GM heads will take a standard length set of head bolts but you mighr try the aftermarket for heads. Edelbrock's BBC heads need four different sized head bolts because they've designed the runners differently to make them flow more like rectangular port heads.
Be sure that the cam you are buying has a stepped nose for a factory roller Mark-VI block. You need this for compatibility with the thrust plate and the single-roller timing chain that leaves room for the reluctor wheel. That brings up another point - don't bother trying to replace the timing set.
Unfortunately roller rockers do not fit underneath the factory low-profile valve covers. The placement of the throttle body over the passenger side valve cover restricts the use of taller covers. In order to install roller rockers and taller covers you'd need to fabricate some plenum spacers to go between the upper and lower manifolds. I'm going to eventually be doing this myself, but it's a ways off. Keep in mind swapping the cam that the factory rockers are not adjustable. New pushrods will be required because the new cam is likely to have a different base circle diameter than the stock one. Big block have two different length pushrods, about 1" difference between the two, and are sold in custom lengths in sets of 8 for that reason.
If the new cam can better get the exhaust out you'll find it will accept a lot more timing advance in the top end. Have you ever looked at the stock timing curve on an L29? It falls off past 2400RPM and never gets past 13 degrees at WOT. Pretty pathetic.
If you're willing to run a 180 degree thermostat and Premium Unleaded fuel, I can tell you that completely stock, it will take an additional SIX DEGREES of timing in the upper kPA with absolutely no knock retard. (That's a huge increase.)
Be sure that the cam you are buying has a stepped nose for a factory roller Mark-VI block. You need this for compatibility with the thrust plate and the single-roller timing chain that leaves room for the reluctor wheel. That brings up another point - don't bother trying to replace the timing set.
Unfortunately roller rockers do not fit underneath the factory low-profile valve covers. The placement of the throttle body over the passenger side valve cover restricts the use of taller covers. In order to install roller rockers and taller covers you'd need to fabricate some plenum spacers to go between the upper and lower manifolds. I'm going to eventually be doing this myself, but it's a ways off. Keep in mind swapping the cam that the factory rockers are not adjustable. New pushrods will be required because the new cam is likely to have a different base circle diameter than the stock one. Big block have two different length pushrods, about 1" difference between the two, and are sold in custom lengths in sets of 8 for that reason.
If the new cam can better get the exhaust out you'll find it will accept a lot more timing advance in the top end. Have you ever looked at the stock timing curve on an L29? It falls off past 2400RPM and never gets past 13 degrees at WOT. Pretty pathetic.
If you're willing to run a 180 degree thermostat and Premium Unleaded fuel, I can tell you that completely stock, it will take an additional SIX DEGREES of timing in the upper kPA with absolutely no knock retard. (That's a huge increase.)
#10
I got the Comp Cam roller rockers to fit with stock valve covers. I bought the kit comes with cam lifters pushrods roller rockers and all the good stuff and a chain adjustable one . Its going to be tuned this tuesday cant wait.



