slow95z

iTrader: (33)

i am building up my 427 and instead of resleeving the LS1 block it looks like the easy way to go would be to just get the LS7 block since its the same boe and stroke from the factory. is there anything i would need to change out or swap (already have the 427 internals from a buddy) so i rather not buy a complete shotblock. another option is to go with the 6.0 iron block and work it up but with so many options out there i have no idea which one to pick. i want it to be done right but also want to stay on a good budget.

StreetnStrip

iTrader: (7)

I would just buy a good 402 or 408 and use the L92 heads.

slow95z

iTrader: (33)

i already have a cam and some heads from the engine just i cant make up my mind on which block to use.

Stang's Bane

iTrader: (22)

I think what he is saying is sell what you have and use the 402 or 408 with l-92 heads. do you have a 427 in your 98 already or is it the one you are talking about building?

slow95z

iTrader: (33)

well i have everything i need just i cant decide on getting a new block (and which one if so) or going the darton sleeve route on my current block. heads are of no concern atm nor is cam just simply wanting to know which route to go with the block. for the price of getting darton sleeves on my LS1 block (and then the warter pump and crazy expensive fluid) i could buy a different block.

03 BUSA

iTrader: (25)

I am building a 427 for my 98 right now and we are using the LS7 block with the L92 heads. Give Trevor over at TSP a call he can give you all the info you need. It is basically a straight up swap, the only thing I need is the cam position sensor extension harness. I am reusing my pushrods, lifters and exhaust rockers, bolts, oil pan, oil pick up tube and such. My original motor had very low miles on it so reusing these things were not an issue.

slow95z

iTrader: (33)

ok, so basically i just stick all my guts in that block without much work. other than what you said are there any other things i might need to adjust for it to work? all the sensors plug up in the same place and stuff right? never even seen the LS7 in person yet so i dont know much about them or even an LS2 for that matter.

03 BUSA

iTrader: (25)

Depends on what you mean about put all the LS1 guts in that motor. It will accept LS1 stlye heads, if you are using LS1 style pistons on a 4.125 bore. The camshaft needs to be on an LS7 grind due to the cam shaft position sensor reading from the front of the motor. Intake can be any LS1 style intake if you use the LS1 heads. Your lifters, rockers will work, only if using your current heads.

slow95z

iTrader: (33)

yes, i am keeping my current heads. bascially the only reason i want to go to the LS7 block is for future upgrades and the cost of darton sleeves plus installation is about the same as just buy the LS7 block.

03 BUSA

iTrader: (25)

You should be good to go. Just know that there will be alot of power left out on the table using those heads. Just fyi. Also, you need to open the chambers on your current heads to the 4.125 bore and revalve. That cost is going to be about $800. So for a set of ported L92 heads at $1499, that would be a waste of $800. You will never sell those heads to someone else with a 427. You seriously need to look at a set of L92 heads. Just my .02

Bring the Noise

The part I bolded is an incorrect statement.

The Cam will need to of a grind to match the heads.
How ever you will need to use a LS2/Ls7 timing chain set and cam timing sensor if you use the LS7 block.
The sensor is on the timing wheel for the LS7/LS2/L92 where on the LS1 it was on the cam.

Now you can not put a LS2 cam into a LS1 motor due to the cam not having a sensor. Well if you had a sensor installed you could, but who wants a ls2 cam anyway?

Ironicly I have a LS1 cam in my motor with the ls1 style sensor on the cam doing absolutely nothing. The timing wheel sensor and timing sensor pickup on my LS2 work just fine.

Now as far as the internals you plan on using in the LS7...
Is the crank your friend has a LS7's dry sump crank with 58x timing wheel or is it a ls1 stroker wet sump crank with a 24x timing wheel.
That will be one of the major things you will need to know before building the motor.

Just a rule of thumb when dealing with LSx based motors...
The cam and manifold need to match the heads.
LS7 heads need a ls7 manifold and cam designed for LS7 heads
LS1 heads need a ls1 manifold (LS6/or fast) and a cam designed for the ls1 heads in question
L92 heads need a L92 manifold (truck or L76 car) and a cam designed for the L92 heads in question

slow95z

iTrader: (33)

i have an LS6 intake and LS1 stroker crank currently. i might just save up the cash for the different heads if its going to be a problem. since i know someone who would buy them already and same on the cam but it would put me a few months behind schedule but i guess its no biggie. with the crank i have what mods are needed to make it work correctly?