how do i know which crate i have?

[GMC Guy]

before i bought my truck the previous owner had installed a GM crate motor. now which one exactly is what i don't know....

it looked most like this one when i first got the truck, but i think there are a couple variations that look alike.
http://www.summitracing.com/parts/NA...7353/?rtype=10

then there's this one...
http://www.jegs.com/p/GM-Performance...52506/10002/-1

basically i would just like to know, how do i figure out which GM crate motor i'm working with?



the PO didn't buy the motor through summit or jegs, but i think through Groth Bros.

[STOCKISH]

Get the casting numbers off the back of the block just behind the driver side cylinder head. You can look up GM casting numbers at mortec.com

[Damien]

That is the same engine. This is from Summit's website. Click on the "show all" link and it will give you the specs. The hp depends on if you are using the stock intake and exhaust or aftermarket intake and headers.

"These GM Performance Goodwrench 5.7L/350 c.i.d. engines have approximately 8.5:1 compression with an base horsepower rating of 195 hp and capable of up to 260 hp depending on intake and injection setup."

[joe231]

First off I'm going to assume it is a 2 piece seal engine with the perimeter bolt valve covers......they are all the same basic engine but with different cams. I don't know how you would know what cam you have unless you pull it out. My crew cab I just bought has the 250HP 10067353 crate engine (luckily the PO kept the receipt for the engine)

http://www.jegs.com/i/GM+Performance...67353/10002/-1

then there is the 290HP 12499529

http://www.sdpc2000.com/details/gm-p...parts/12499529

and a 300HP 10067353

http://paceperformance.com/index.asp...&ProdID=264227

if you notice in the specs they all have the same basic specs (block, heads, ect), but with different cams.
can you tell I have recently been researching this for my engine

[Damien]

Everything Joe posted is correct. The two engines posted by GMC Guy have the same cam specs.

[GMC Guy]

so basically there is no way to determine which one it is unless pull the cam? lol

i understand better now though, thanks for setting me straight.

[MR .T]

you could check cam lift with a dial indicator. that will give you a good idea of what cam it is. stock is 390 lift L79 is 447 those are common.