408 or 370 for F.I.
Dec 30, 2008 | 07:12 AM
#91
I like the GT2-3 too, and planning on using it in my 5.3L rebuild...but, u can't pick a cam without first knowing exactly what valvetrain & heads are in the build. The goals u set out for driveability and performance, as well as CR and boost will be bigger determinants of the mating of valves, springs, lifters and ultimately heads. The cut of the valves and spring rate have a huge impact on maximizing power from any given cam - they will determine where u make ur power along the curve. Rex & Richard should be able to help u as well as many others prob, but Comp, Lunati, ...etc, will have done much of this work and will recommend a valve train package to mate with most of the cams in their catalogue. Do some homework here, don't just take someone's word for it. If ur gonna use the AFR heads u already have, get the specs on the valves & springs, then see what cam will maximize their design given ur goals & application - or consider changing those pieces to match up. R/
Last edited by dhpro; Dec 30, 2008 at 07:18 AM.
Dec 30, 2008 | 02:18 PM
#93
If I understand this correctly, thunderwagen, don't you already have the GT2-3 cam in your boosted 6.0L now? It is my understanding this 408ci build is only changing the rotating assembly, thus the displacement under the heads, correct? Why does there need to be a significant redesign of the valvetrain and top end if what you have is already working? Perhaps I'm missing something...? 
Dec 30, 2008 | 02:20 PM
#94
Dec 30, 2008 | 03:51 PM
#95
If I understand this correctly, thunderwagen, don't you already have the GT2-3 cam in your boosted 6.0L now? It is my understanding this 408ci build is only changing the rotating assembly, thus the displacement under the heads, correct? Why does there need to be a significant redesign of the valvetrain and top end if what you have is already working? Perhaps I'm missing something...?
Dec 30, 2008 | 06:48 PM
#97
The reason for cam change is the GT2-3 is more of a blower cam and if I still had a magnacharger I would more than likely leave it. I also feel it is a little on the small side for a 408. I think there will be a more optimal cam for a 408 turbo application than what I already have.
Dec 30, 2008 | 07:58 PM
#98
Believe me I know all about murphys law with this truck. The only plug and play thing I have ever done to the truck was the Radix. After that I broke more stuff and spent more money than I ever thought I would. And after going turbo I have gone through two different setups and fought little problems the whole way. I don't expect it to be trouble free or snap together like leggos. Im not building it myself. I am between going to LME, HKE, and having Rex build it.
Jan 1, 2009 | 09:50 AM
#99
There is no reason that a stroker motor should burn oil if the builder knows what he is doing. I've had a Rex 408 and now a 403 and have had ZERO oil burning issues. The first one died because the turbo was too small and I spun it up too much. Heat and backpressure killed it.
If I were to do it over again, I'd run a 402. Don't mess with the boring of the block unless it's necessary to clean up the cylinder walls. You are not going to miss 6 cubic inches. My setup is about 9.4:1 and seems to be a pretty good combination for street manners and boostability (new word!
) I'm running a 220/222-580/580-114+1 cam spec'ed by Richard @ WCCH and could not be happier with the combination of power and driveability. I only spin my engine up to about 5600 RPM, and with the GT4202 turbo I run I am making full boost by about 2600 RPM. You can imagine what the torque curve for that would look like.
If I were to do it over again, I'd run a 402. Don't mess with the boring of the block unless it's necessary to clean up the cylinder walls. You are not going to miss 6 cubic inches. My setup is about 9.4:1 and seems to be a pretty good combination for street manners and boostability (new word!
) I'm running a 220/222-580/580-114+1 cam spec'ed by Richard @ WCCH and could not be happier with the combination of power and driveability. I only spin my engine up to about 5600 RPM, and with the GT4202 turbo I run I am making full boost by about 2600 RPM. You can imagine what the torque curve for that would look like.
Jan 2, 2009 | 11:52 PM
#100
There is no reason that a stroker motor should burn oil if the builder knows what he is doing. I've had a Rex 408 and now a 403 and have had ZERO oil burning issues. The first one died because the turbo was too small and I spun it up too much. Heat and backpressure killed it.
If I were to do it over again, I'd run a 402. Don't mess with the boring of the block unless it's necessary to clean up the cylinder walls. You are not going to miss 6 cubic inches. My setup is about 9.4:1 and seems to be a pretty good combination for street manners and boostability (new word! ) I'm running a 220/222-580/580-114+1 cam spec'ed by Richard @ WCCH and could not be happier with the combination of power and driveability. I only spin my engine up to about 5600 RPM, and with the GT4202 turbo I run I am making full boost by about 2600 RPM. You can imagine what the torque curve for that would look like.
If I were to do it over again, I'd run a 402. Don't mess with the boring of the block unless it's necessary to clean up the cylinder walls. You are not going to miss 6 cubic inches. My setup is about 9.4:1 and seems to be a pretty good combination for street manners and boostability (new word!
) I'm running a 220/222-580/580-114+1 cam spec'ed by Richard @ WCCH and could not be happier with the combination of power and driveability. I only spin my engine up to about 5600 RPM, and with the GT4202 turbo I run I am making full boost by about 2600 RPM. You can imagine what the torque curve for that would look like.
