1998 t/a

iTrader: (3)

Building an LQ4 and just getting ideas to paper as I tear down the motor and get it read to go to the machine shop. We are trying to keep this as budget friendly as possible but I don't mind cracking open the wallet if it is going to beneficial for me to do so. The goal for the engine is to not make the worlds most horsepower but have a stout motor I can boost later on. With that being said I am tossing around what to do with the top end. I have the stock heads that came on the LQ4 and I have heads off my 98 Camaro sitting in the shelf.

Option 1-Port the LQ4 heads go with an LS6 of FAST intake to top it off
Option 2-Port the LS1 heads off my 98 LS6 or FAST intake
Option 3-Ported LS3 heads with LS3 intake

*Trying to keep it budget friendly but from what I'm seeing LS3 top end is very affordable.

I don't know if one head is better than the other when it comes to what came stock on the LQ4 vs my 98 LS1 thats why I tossed them both up there. if there are benefits to running my ported 98's versus the LQ4 I would go that route. Both heads look like they are in good shape. Any opinions are welcome, I know the cam has a lot to do with this so I would go with a mild cam, maybe a BTR stage 3 and swap a blower cam when it comes time to do the supercharger.

Haggar

If your goal is decent now, but boost friendly, I would investigate LS3 heads (stock, not ported/milled) and an LS3 / Gen IV Truck intake.

Stock LS3 heads and ported 317 heads will probably be very similar in power. The 317 will make more torque below 4000 rpm from all comparo's I've seen, the LS3s stock will outflow the ported cathedral ports and make a few more HP up top.

Do a cost comparison of the options. Machining & port work on 317s might be just as expensive as a set of LS3 heads, and a FAST, Dorman LS2, or LS6 might be just as much as an LS3 intake.

FWIW, my GMC runs an LQ4 with ported 317s (stock CCs, not milled). With a 223/231 cam, its very strong. I think any of those combos would be fine for a 500hp setup, just depends on cost and parts availability.

1998 t/a

iTrader: (3)

ya this is exactly why I threw the LS3 set up on here as an option. My understanding is they are pretty good heads in stock form and a pair cost about as much as a port job. Appreciate the feedback! While I got you, We're not breaking records on power, do you think the stock crank and main caps will be OK?

grinder11

iTrader: (1)

I'd go with LS3 heads if it was my build. Stay away from the LS2 intake, if you must go cathedral. Your stock crank and main caps should be fine, up to a point. I'd say that point is arguable, but in my mind it's good to 550-600 crank hp. HOWEVER-This assumes no missed shifts/overrev to 8500rpm type situations. Many people don't realize that a lot of forged equipment is there for insurance. Ti retainers, forged pistons, forged crank, etc., help virtually nothing, until there's an unexpected problem, like an 8k rpm missed shift, or some worse than expected octane causes a bad spark knock. As for your heads, I'd absolutely go for the LS3 heads. Then there's this, if you stay with cathedrals: it isn't possible to port LS1 heads to equal the flow of LS3 heads, or ported LS6 heads. Yes, LS1 heads can be ported to outflow UNPORTED LS6 heads. Port them both, and the LS6 holds all the cards.......

1998 t/a

iTrader: (3)

Good points, thank you for the reply. I *want* to keep it budget friendly but I'm fully expecting to build over time and the budget could open up depending on what happens with work etc etc and I may have some additional funds. The goal would be to upgrade pistons and rods but run stock crank and end caps...although I know it's good insurance to upgrade endcaps but from what I've read the end caps and crank can handle it and upgrade the hardware with ARP bolts.

G Atsma

Define "endcaps".
Main caps? These are 6-bolt and are quite strong thru 1k HP.
Rod caps? You don't replace those. Use what comes on whatever rods you use.

SoCalDave

LS3 heads are good. One other option is find a set of stock 862 heads off an 5.3 LM7 and have those ported. 862 heads can be found cheap at a junkyard.

LilJayV10

iTrader: (39)

Yeah I really didn't understand the point of his post considering the context of the OP's post.

OP,
LS3 heads, LS3 intake, boost it.
Done.

Kawboom

There is an argument to be made for ported cathedral port castings. The LS3 heads are pretty good, but also big ports and expensive. I personally don't trust Joe Somebody head jobs, and if you had a good shop do the porting they would also do a reliable good valve job on the heads and your new valves.

Just an idea.

99 Black Bird T/A

iTrader: (4)

I'd pick up these FI proven FlowTech Induction CNC ported AFR 225's for $1,500 and use them. I think the thicker deck would be nice if you really crank up the boost.

A set of LS3 cores for $700, valve spring set ~$300 plus valve job & bowl clean up will likely cost as much as the heads listed above.

Add Summit Ghost Cam and cathedral intake of choice.

1998 t/a

iTrader: (3)

Yeah I'm tarded, sitting at home the last 2 days getting over a fever my son gave me from day care lol. I meant main caps. But I'm leaning heavy on the LS3 set up right now. Should get the block to the machine shop this month and then I'll be buying up parts.

G Atsma

OK. That being said, the stock main caps will be fine.

cula8r

iTrader: (2)

A few years back I ended up using LS3 heads(updated the springs) on my N/A 6.0L block and couldn't be happier. As an alternative to the LS3 heads with out the lightweight valves consider GM LSA heads. They are about 200.00 a piece cheaper and came on the supercharged ZL1 Camaros. This way you could use the LS3 intake and later on boost.
https://www.summitracing.com/parts/nal-12675872
Pick your preference on cams:
https://www.motortrend.com/how-to/hr...gine-cam-test/

1998 t/a

iTrader: (3)

thats informative, thank you!

KCS

iTrader: (20)

This is what I would do personally since you are working with an LQ4 shortblock with dished pistons. I probably wouldn’t even fully port them, just upgrade to 2.00” or 2.02” intake valves, cut a valve job, bowl work, and skim cut the deck. Easy 10.5:1 compression ratio without even milling the heads.

1998 t/a

iTrader: (3)

I'm going with a forged rotating assembly

jetech

What kind of power you looking to make? What rpm limit?

Tuskyz28

Really depends on your horswpower goals. This video have lots of information.

1998 t/a

iTrader: (3)

Looking to make in the 500-530 N/A then boost down the road.

KCS

iTrader: (20)

That would still work great. Since the 5.3L heads have the smallest chambers, you can get good power with the higher compression, and then swap heads when you’re ready to boost it for a safer compression ratio.