A forged 408 is cheaper than a forged 370 anyway, because of the proliferation of parts for the 4xx motors; parts for the forged 370's are rather expensive in comparison.

 

Didn't know about mototron, I went to a FAST which controlls any injector. No trade-up was available, bought the T. (Not from Vortech, look for a deal) I keep advising people - Lose this fixation on high boost! It's meaningless. When my truck was mostly stock, I got 14# boost with a 7in crank and a 2.5 in s/c pulley.(lots of slip, heat, and spark retard.) I added big intake, heads, cam, tb, aftercooler, freeflow exhaust, spark upgrade, 10 rib 8in x 2.5in pulleys, 8:1cr, new s/c, etc. and now it has a "measely" 12# boost. Yet my engine requires 72# injectors to get enough fuel, has at least twice the hp & tq and runs much cooler. I am thinking about some new AFR heads which I am sure will give me even less boost. If you want high boost, get a smaller intake, if you want more hp, look for more air flow. If you reach the limits of size then look at boost. Sorry, off the soap box. The T flows great, but if I knew I was going to do as much as I have, the engine needs a YSi now. I was worried about going too big and surge is a concern. Actually, big horsepower is easy, the real problem is breakage and getting it to the ground.

 

Disagree with that. But then again, I wouldn't be interested in a rock bottom dollar forged assembly anyway, let alone a mail order assembly, except for very few exceptions(like 1 maybe 2 companies). Typically the 370 is 300-500 cheaper. A 3.622 stroke crank is a stocked item, as are 6.098 rods, and corresponding pistons.

 

Disagree all you want, doesn't change the prices.

 

My only hessitation with spending top dollar on a forged motor is that I have heard so many horror stories about failing "built" motors. This truck is my toy and I dont mind paying for stuff when it breaks, but if Im going to get the same life out of a stock 6.0 as I would out of an unfortunate crap build from a builder I would rather go through 3 $800 6.0 shortblocks as opposed to 1 5K 408. To my knowledge no one offers any type of guarantee with there motors especially if boosted.
At what point is a forged motor a must? I was also thinking that I could do a nice set of heads on a stock bottom end 6.0 with a T trim. If I over do it than I could back it down a bit and get another cheap 6.0 shortblock. What do you guys think? Im just throwing things out as they come to me.
AintNoHO, I understand the relation of lower boost to actual airflow, I didnt explain well enough I guess. The S trim has a CFM rating of 1000cfm, the T trim has a rating of 1200cfm. Do you think that is a decent return on the $2000 price tag or would the money be better spent elsewhere?

 

All valid concrens. For me personally, I always try to go with a relatively local, reputable, machine shop for the services I need performed. The main reason being recourse and relationship.
I believe a mostly stock shortblock(forged pistons, high strength rod bolts) can last a long time as long as you are a good tuner or have ready access to one, so you have a greatly increased chance as to not subject your engine to lean conditions or detonation.
As far as thr return on investment for head units(or the whole project for that matter), to me, depends on your end goal and how close to the limit you would be pushing the S Trim, to justify the larger unit

 

The T trim is a much more efficiently flowing charger. It overlaps on the low rpms enough so you wont have surge yet is greatly cooler on the higher rpms.
It has heavy duty bearings for a very tight belt or even a cog set-up. (I had my SQ rebuilt for $600 because I cranked the belt so tight to stop slip) The T is also very noisy because of the straight-cut gears (some like that) and is not smog legal (why I keep my SQ). Do I think it's for you? No, not til you get a forged bottom-end. I've broken 2 cranks learning that. First was Summit iron, second was Scat forged. I recommend Eagle or equivalent U.S. quality steel forged. By the way, some folks report forged piston trigger the knock sensor. I don't know, I dont use a ks.

 

The max efficient impellar speed is 45K, the max speed is 50K.
Im at 58327. Figure in a 10% slip and that puts me at 52494. Im not the best tuner, but I have a wideband and HPtuners. Ive got the basics covered. There is a shop down the street from my office that is a sponser on LS1tech. I'll swing in there and see what they say. I dont remember them having very good prices though. If I remember correctly they wanted $800 -$1000 to install a cam and springs.
Have you installed those heads yet? Im very curious to see what they do for your setup.

 

I agree, I have been doing the research on the 402 and have found that it is only 3-400 more than a smaller displacement forged motor. I say go big or go home!

Hey Kevin, what are your plans for the new TBSS?

Green, I agree with you 100%.....making these changes to a daily driver is just nuts IMO....too much of a risk of breakdown.