69chevelleguy

I am trying to build 5.3L LM7 motor for my Chevelle. I was wanting to make a stroker to around 396ci but after reading a bunch and talking with people, I think the better way to spend the money would be just to do a cam swap, with headers, ls1 intake. etc. My questions are, do I have to change the heads to put the LS1 intake and injectors on the 5.3? and what cam should I get? and if I change the cam do I have to put hardened push rods and different valve springs in it? I heard that the 02 LS6 cam was a good option to wake up the 5.3 and with some headers and the LS1 intake would make good power and would have good economy. I am not looking to make a screamin' machine just something to have fun with now and then. I am planning on going with a T56 but I heard that the LS6 cam would not give me very good low end. Since I have 3.55 gears in the car and with that 6th gear in the tranny being high, I don't want it luggin' at highway speeds, ya know?

Advice would be cool from you all of you fine people at LS1tech that know more than I do. lol

mvrotc

iTrader: (4)

first off dont waste your time with the ls1 intake, pick up an ls6 one from the boards on here, itll work out much better for you and no you dont have to change the heads to use that intake.

Second if your gonna do a cam swap , do a an actual aftermarket cam not the ls6 your gonna wish you went bigger later on (been there). If your not looking to go crazy i would pick up a comp cam XR265HR , which is a 212/218 on .522/.529, this will allow you to use the cheap ls6 valve sprigs, but no matter what cam u need to do hardened pushrods. If you wanna go slightly bigger the 220r from TSP with the 580 lift is an EXCELLENT cam for the 5.3l , if you go on the truck forums youll see many people get great numbers from them

batboy

iTrader: (6)

Like was said, don't bother with a LS1 intake. Use the LS6 intake or if you have room under the hood, just use a truck intake (they make great torque).

What injectors you use depends on the fuel rails you have and wiring harness.

A cam swap should include upgraded valve springs and hardened pushrods. Most vendors have cam kits with everything you need. A 2002+ LS6 cam would work, but there are better cams available. The 212/218 Comp Cams that was mentioned is popular with the 5.3 truck guys because it has lots of low end torque and you can use a stock torque converter. Since you are not as heavy as the trucks and are using a manual trans, I'd go a little bigger. The Texas Speed 220R would be a sweet choice.

AR's LSnotch

How about the XR281hR 0.571/0.573 lift split 228/230 duration on 112 LSA I hear ther very good on the 5.3s I'm in the same boat on tryng to choose a cam still tryng to find more information runing the Texas speed ms3 237/242 603/609Lift 111LSA an 243 heads

batboy

iTrader: (6)

The OP was wanting a cam that had good low end torque that wouldn't lug in high gear. AR's, sounds like you want something bigger, which is cool. I would not get a MS3 for a 5.3 motor though, you won't like the street manners. Take a look at Tick's SNS torquMAX stage 2 cam.

AR's LSnotch

I kno bigger is not always better but I been reading ppl making great power with the ms3 an my coupe won't be DD just weekend car an a lil of track but looking for a cam that makes good power with 243 heads an of course I'm looking for that nasty chop

batboy

iTrader: (6)

Just my opinion, but the MS3 cam uses the old aggressive XER lobes and is too way too big for the 5.3 (you'll have nothing in the low range). PM or call Martin with Tick Performance and see what he recommends.

AR's LSnotch

Sure will thanks man just tryng to get my info straight am new to this LS world

batboy

iTrader: (6)

If you are looking for a idle lope or chop, a lower LSA will give you that without going too big on duration. The SNS torquMAX stage 2 cam I mentioned earlier has a low LSA. Listen to one of Tick's sound clips (follow the link at the bottom). With a smaller displacement motor like the 5.3, you'll probably have even more lope.

http://www.tickperformance.com/tick-...1-ls6-engines/

AR's LSnotch

How good would that cam do wit my 243 heads an am also thinking of running a 4L80e or a turbo350/400 kinda wanna make my coupe just to punish it in street racing

batboy

iTrader: (6)

Should work fine with 243 heads. Might want to mill the heads about .020" to regain compression (unless they are alrready milled).

AR's LSnotch

The heads don't have no work done to them an if mill to .020 how u say about we're would I be in compression

batboy

iTrader: (6)

Same as with the 5.3 heads. As for exact CR, I would need to know piston dish volume, what head gaskets, and deck height.

AR's LSnotch

Pistons are flat not dish an for deck height I would have to get back at u on that is a 2007 5.3 an wat head gaskets do u recommend

batboy

iTrader: (6)

Personally, I'd use the GM MLS gaskets, they seal up the best. So, pistons are true flattops with no valve reliefs? If so, using average deck height, you should be at about 9.5 CR.

AR's LSnotch

9.5 cr wit milld 243s right . As for head bolts should I use oem or go for ARPs or I been hearing Thers other type studs an ther cheaper then ARPs

batboy

iTrader: (6)

Right, I figured 234 heads milled .020". Milling them .030" would give you another quarter point of CR or you can use Cometic .040" gaskets instead of the GM ones. I use ARP bolts because they are reuseable. The GM bolts are fine, but they are TTY and can only be used once. As for studs, I'd still use ARP. Not heard much about other brands.

69chevelleguy

I would love to use the truck intake but it wont fit under the hood. I could get a cowl hood but my car is a SS so I want to leave the original hood on it. That being said the injectors depends on the wiring harness. so I should get a harness from an F-body then right?

69chevelleguy

What about the heads? should I go with a different head than the stock truck head, again just trying to build a cruiser nothing really sick and nasty. What injector harness is the right one.

batboy

iTrader: (6)

If you use a F-body wiring harness, then any injector that will fit a LS1 will work. Just use the LS1/LS6 fuel rail if you plan on using a LS6 intake. The truck 5.3 heads are not bad and they keep the compression up. Of course they would be better ported or at least milled a little.