Lumps are not necessary @ this point.Will they help? sure they will. The turbo is going to force the air & fuel into your engine & having a better short turn radius is not as critical as when the engine is naturally aspirated. But you need to open up the intake port windows to allow more air/fuel to get into your engine. Meaning , you need to profile/make smaller the intake bosses. Do some bowl work & the short turn radius'. Port the exhaust port all the way through & a good valve job.
Installing oversized valves,rough estimate approx $10-15 each so that's $120-$180 bowl work/porting can vary a lot. $200 to $400 & up It's not cheap, & you should not skimp there if you want to make some good power. Valve job, guides installed $125-$200 surface head. $40-60. It all adds up to a lot, but this is where all your power is going to be coming from, a great flowing cyl head.
If you can do some of the porting yourself & you can save some $, but you can cut/grind into water jackets if you go too far.So you would need to be carefull.
W/a good head gasket & stock head bolts I can see you running 15 lbs of boost w/no problems.
What I think of low boost is about 10 psi or less. The lump port kit should come with special head bolts.
You could buy the lumps & it will improve the power output, just not as much difference as if you were just running a naturally aspirated engine, (again, the turbocharger is forcing the air/fuel mixture into the engine,so it is not a critical.) You need to make sure your intake port window are larger than stock in order to flow more along w/the larger 1.94" intake valves. I would only profile your cyl intake boss & that alone will open up your intake port window & still have some high intake port velocity.
As far as the J&S goes, yes it's pricey, but it will save your engine.
Alternative, you could just buy an MSD boost timing master box. You would set how much timing you want to take away per psi of boost pressure. It works, just not as safe.It cannot detect knock.
It cannot sense if your engine is detonating as the J&S does when using a knock sensor.
If you keep your boost low, approx 10 psi & conservative on the timing, you would not need methanol injection. But you need an intercooler for sure.
I know all this sounds expensive, but you should see how much time & money guys put into a high power turbo set-ups,shocking
It's all the initial parts that cost money.
You could just throw your turbo onto your engine & that would be a low buck turbo install. That is what I call a low dollar turbo install.Put a turbo onto your engine that is in your car, add an intercooler & all the little odds & ends. That's a low dollar turbo install. It will not make make that much power either. Plan & simple speed cost money. You want to run 12's, You are making the engine swap choices, cam swap, etc etc etc. It all depends on how fast do you want to go? Speed cost money & a 6 cyl turbocharged Chevy build is not cheap.
Guys are putting junkyard Chevy LS engines into there old cars, run the stock exhaust manifolds flipped around backwards & add a turbo , intercooler etc etc etc, those builds are cheap & can make a-lot of power, they are still not doing the swaps for just $1000 dollars, you add up all the parts & guess what it still adds up to more money than you would want to spend.
So the choice is yours on what you want to do.
If you want a low dollar turbo charged inline 6. Re-ring & bearings, ARP rod bolts, resize the rods, install a turbo camshaft & lifters.Good headgasket.That is a low dollar turbo set-up. It still costs money.
