onebadbowtie86

iTrader: (13)

Shop missed the mark on the cam. 236* intake duration and 116 lsa for a 650 hp 408? Needs more duration and less lsa for your power goals.

Y2K_Frenzy

Just pay the 550 horse price maybe and move on

BFromTheD

I have a difficult time believing they advertise 650 with this combination of parts. Looking at that dyno sheet, this engine did exactly what I expect. A lot of engines with detailed threads on this site have similar combinations and make similar power. Makes me wonder where they got the 650 number from.

At the shop I worked at pretty much every engine advertised on the website when built and put on the dyno will put out within 10 hp of the number unless customer changes were specified.

SlowTBSS

Sounds like the shop over promised and under delivered! I wouldnt expect 650hp from that combo of parts and honestly a lot of it is mismatched to even try and make the power. My 402 made 662fwhp without the vacuum pump on it. I have 11.8:1 CR, Mamo 235 heads and cam specs are 243/249 .675/.675 w/1.8 rockers, Johnson short travel lifters, Mamo Ported FAST LSXrt manifold with NW 103 TB. Runs perfect on 93 pump gas as well. My cam is out of breath by 6500, I imagine yours is done before then. You also have a LS3 intake which would need serious porting/rod mod to make those numbers, let alone the 90mm TB acting as the first choke point. Also 1 3/4" headers were down 10-12hp from the 1 7/8 headers. Definitely doesn't seem like you have the parts to make the numbers promised sadly.

Here's a link to mine if you want to browse through and get an idea of what 650+ takes.
https://ls1tech.com/forums/dynamomet...gas-build.html

Ls7colorado

iTrader: (3)

That flat torque curve and those power numbers would be crazy fun in a street car like others have said.
I would try and negotiate the price IF it was inflated to match the extra 100HP goal. But again like others said, that combo making 560+ HP at 6000 rpm will be much easier to drive, and more reliable than making 650hp @7500 rpm
If your not happy and you have the funds, just throw that supercharger on there you know you want anyways lol.

LS1Formulation

iTrader: (13)

I suddenly don't feel bad about my cam only LS3 making 466 to the wheels, lol. Ouch man, you got hosed. Hope they do something to make it right.

pannetron

What was the ignition advance? It's easy to kill heads with a "hand ported" job.