I have a 99 T/A with 91k on it. Stock long block car right now. I have a buddy selling me an 01 LQ4 for really cheap. Trying to decide if it's worth swapping it out. I'll toss my ported fast that's on the LS1 on top with some 243's I have sitting in the basement and let it eat if I do but I'm still undecided. Near 90 pounds if I recall correctly, to add to the front of the car is a considerable amount.

I guess I'm really just trying to soak up some knowledge from folks that have done it.

If I do it, I'll probably swap a cam in at the same time. Anybody have any combos that have worked well for them? Raising the compression via thinner head gaskets and milling the heads sounds good but I don't want to limit cam selection too much. Also don't want to flycut and shoot myself in the foot when I start spraying the motor.

For those of you who have done this, what combinations have you run? (head gaskets, milling, cam) Any suggestions would be appreciated.

Thanks in advance for the help.

Josh

 

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IMO, go cam, keep the aluminum block. Stay light and make almost the same power. Your 243 heads. A little porting if it fits your budget.

 

I'm just afraid that it will be a bit much for it when I spray.

 

I swapped to a forged LQ9 when my LS1 blew. Also swapped over my LS6 intake, PRC stage 2.5/5.3 heads, but went with a bigger cam and more compression this time. The cam is almost identical to the MS3. Even though it added a little weight it is significantly faster than the old LS1 setup. Running a 100 shot right now and will eventually run around a 300 hit once I beef things up a bit

 

ok cool. I'm thinking it's worth it. Especially once I start spraying.

 

How much spray? Unless it's 200hp or more use the 243s and get a cam for your motor.

There isn't much to gain with a stock lq4 that you couldn't just do to your LS1 anyway.

 

I was thinking right at 200-250. If I keep my current motor I'd probably just buy the LQ4 anyway because it's going to be so cheap. I'd just save up and 408 it. My rod bolts also scare me in the LS1. I'm so bad at making decisions.

 

In that case it might be worth it to swap and sell your engine. You will likely come out ahead as a low mileage ls1 is worth a decent bit.

 

More displacement never hurt anyone. Would be worth it if you can sell your LS1.

 

Go for it there is so much more power to be gained. But you will also gain weight on the front end around 100lbs or so

 

Swapping to a forged 370 makes sense you gain a lot of strength, 24 cubic inches, and compression, thats not a bad trade off for the weight. Going to a stock LQ4 you only gain 18 inches and you loose compression, I'd say the inches and compression come close to canceling each other out leaving you with only added weight.

 

I severely doubt the inches even come close to making up for the weight/compression trade offs. Just seems the truck engines take larger amounts of spray better.

 

I don't understand where all the power to be gained would come from the short block swap. You will go to a dish piston, add 100lbs and have to do an engine swap. Unless you plan on building a forged bottom 408 the LS1 should handle as much nitrous if set is on. Stock bottom for stock bottom LS1>LQ4.

 

He said he is might build the lq4 if he buys it. So the 6.0 will defiantly make more power than the 5.7 will. And be a better engine to go with FI if the OP eventually decides to do that

 

Absolutely! If I wasn't going to up the compression, forged and take advantage of a larger cam I would've just stuck with the LS1

 

Yes, if! Until then, LS1.

 

Can't I just run thinner head gaskets to help compensate for the lower compression? That and milling the heads should equal that out if not give me more than the LS1 correct? My only issue with that is how it will limit me in cam size selection.

 

No matter how you chalk it up, as long as there are dish pistons in your 6.0 it isn't worth the swap. You are talking about milling, thinner head gaskets just to get back to where you are with the LS1 and it still weighs more. The LS1 will dominate in stock block form. Buy the 6.0 and save your coin to build it right the first time. Nitrous doesn't give second chances.

 

This^^^^