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The other head came in and looks great, gotta call them about some other stuff that was supposed to arrive with the heads but very pleased with the work. Its shiny and I like shiny!
The 243's deffintely like rpm, but they drive very nicely under 4K. Almost like the power isn't there untill you give it some fuel then they are animals and build rpm very fast. I've never had a v8 come up this fast on rpm, it scares people who aren't ready for it. Lol...
I'm sure this is not the most proper comparison but one major factor making me want better heads is driving my buddies 408 Denali with the manual swap. His 408 has PRC 247cnc heads and a fairly aggressive cam although I can not remember the exact specs something in the 23x/24x 114lsa range. Anyway, it's amazing how alive the truck feels after around 3,500-4k and keeps pulling up to 6,500+. Although I understand it's considerably more CI, cam, and head it also feels very strong down low and has no problems with driveability. His truck weights nearly 1k more than mine yet it puts a good bus length on my Tahoe in a 0-80 run.
My truck pulls great but feels like it runs out of steam just after 5,800. Is it foolish to think the heads would help carry power up towards 6,200+?
Lastly how much power do you guys honestly think would be lost under 4k? I'm not having to suffer through driving a loose converter or anything like that, if I want I can be above 4k at 20mph and never see below 4k again.
haha, nice example...
you'd get a whole extra 16mph out of 1st gear (20-36mph) winding up to 7400rpm to hit 2nd & 3rd at 4K (at 66 & 120mph, respectively).
i wouldn't personally bank on driving an nv4500 that way... but that's just me.
let's face it: 1st is too short on an unloaded truck with 3.42 gears & 31s to even factor into the equation, so you'll launch in second on a slip (because dumping in 1st = nothing but BLM 'mural' embellishment) & run that up to 55mph @ 6200, catch 3rd at ~3300rpm, and then run that out to about 100mph @ 6200. if you keep carrying into 4th, you'll catch at 3700 & pull until you either throw the drive shaft or break another yoke.
kinda reminds me of when i sold Penny:
another friend came up to me a week later (because he was also friends with the kid who bought it) & was like, "Holy S#!t dude!!! your truck freakin screams & was all over the place! i never knew it could do that!"
turns out he'd hopped a ride with the saturday night crowd that weekend, and the kid really wound her up just to see how it ran.
i simply replied, "yeah, i know... that's why i stopped taking it over 3K unless i meant business".
let's face it: 1st is too short on an unloaded truck with 3.42 gears & 31s to even factor into the equation, so you'll launch in second on a slip (because dumping in 1st = nothing but BLM 'mural' embellishment) & run that up to 55mph @ 6200, catch 3rd at ~3300rpm, and then run that out to about 100mph @ 6200. if you keep carrying into 4th, you'll catch at 3700 & pull until you either throw the drive shaft or break another yoke.
There really is no tire spinning with this thing even in first gear, unless of course, I dump it at 4k but, I rarely do that when leaving a light I typically leave with a slip/roll into 1st. Also if I shift at 5,800 I catch second at 3,800 and if I shift to third at 5,800 I catch it at 3,450. Shifting at 6,300 would keep me above 4k pretty much the whole time.
Here is a spirited run I did this morning while logging. 1st to 2nd then 3rd but I let out because 80 in a 35 is frowned upon and the dang police haven't been defunded in my town.
Really don't think I'll break this monster shaft or the 1410 yoke/U joint. Especially now that I have the correct pinion angle and got the LCA drop brackets in so the axle doesn't rotate itself to death.
I do agree first is a little short but 0-30 isn't really that quick that it's not a benefit to use for a launch, I find it bogs hard if I try to launch it in 2nd. (Oh boy just did some maths using 4l60 first gear of 3.06 and even with a 4.56 rear gear and 31" tires it can run 42mph at 6k)
07-26-2021, 07:58 PM
