I was with you on all of it except for:
Completely the opposite for me. I don't care about power at 7500 on the street I care about torque at 4k. Lowend torque is fun! Big power up top is racecar stuff.

 

Ok to simplify the goal, let's say you want to keep it at a 10 point cage so you aren't running faster than 8.5 anyway. Say the car is a heavy street car, 3900-4000 lbs race weight.

What engine and turbo combo would spool well on the street at a lower boost level with street friendly cam, stall, etc , while still enabling you to hit 8.5 - 8.7 at the track at higher boost level on 110 octane. Assume you are willing to pay a little more to be durable like spending the $$ on a rotating assembly, ARP, etc so that you aren't tearing into the block every few years, but you want to avoid the extra $$ required stepping up to the aftermarket block. We aren't talking about a 1500hp combo here, more like trying to do this hitting the occasional 1100-1200 rwhp on 110 octane using a factory block. Assume the car is dialed in for suspension at the track, and that you are cutting 1.3 sixty foot times launching off a trans brake in a 4L80E.

 

I Agree!

Point I was trying to get across is an 8.9:1, 2.73 geared, 5.3 will easily make more torque and low end power than you can plant on the street. 650 ft lb at 4k will haze the tires just well at 700-800-900-1000 etc... It's all a smoke show if you cant stick the tire.

 

Right, but we aren't talking about a street car only with no 1/4 mile time goals. Sure you would keep the power down on the street, but I was referring to a scenario where you are running race gas tune at the track to hit a 1/4 mile goal in a heavy car. At the cost level we are discussing, I'd go iron over aluminum for durability at the drawback of the additional weight.

 

Ah, I'm with you now. I swapped back from my 28" DR's to my 315/35/17 street tires....hilarious tire smoke 1-3 gear. Both are fun in completely different ways.

 

You don't need close to 1000hp to run 9's, meaning you don't need an iron block and it'll still be plenty reliable.

 

Eh... the goals are shifting rapidly. Making it to the 9's is one thing. Now you are talking about dual purpose street/strip car going 8.5's at 4000 lbs. You will need over 1000hp to do that. That's a whole new ball park there, big money! Better in my opinion to get 2 cars and make one fast than try and make a 4000lb car have good street manors and run 8.50's. That's a tall order. Esp. if you want any kind of reliability. I wouldn't use any stock block stuff for that goal. Jump right into a aftermarket block and super tough short block. Keeping engines and drive-lines alive at 4000lbs and 8.50's is also hard...aka big $. It makes little to no sense to want a 4000lb race car IMO. But hey if money was no option, why not!

You should also check your facts a bit on Iron VS alum and strength. The block castings are different on the alum 5.3's. They have Siamese bores and are as strong if not stronger than the iron 5.3's or 6.0's. Also if you start boring and stroking the 4" plus big bore stock blocks you make them even weaker. Again, not something you want at 4000lbs and 8 sec power. Only option there is to go with an aftermarket race block if you are serious about it. Then the more cubes the better. Hell a BBC makes more sense at those power levels and weights, IMO.

 

I'm with you. Ideally 2 different cars are needed to do it correctly otherwise the attempt is going to be half-assed unless big $$ as you say. I'm just thinking worst case scenario on the weight because I'm already at 3400 lbs and by the time you add in the cage, iron block, 4L80E and turbo kit it comes out to being a heavy *** car so I'm estimating 3900-4000 race weight. It's either spend the $$ on the aftermarket block and internals (at that weight and 1/4 ET goals), or live with running slower times using the factory block, or pull weight out of the car which will be easier said than done. My comment on the alum vs iron was based on how companies like RED and TSP are sleeving the aluminum blocks to get them to hold more power. Regarding the turbo sizing on the 408, those are what was recommended based on past discussions with places like Precision, Huron Speed, AGP, etc after explaining that I'd like for the turbo to be capable of making 1100-1200 rwhp on a gen iv iron block stroked to 408 without it being laggy as hell on the street in a heavy car with the appropriate cam and stall.

 

Those aren't the turbos I'd choose, but it depends heavily on the setup. A 408 will likely make 600+hp if done correctly. So you'd only run a few pounds on the street, and 14-15lbs will make 1200ish crank. Personally I'd rather lean on a big turbo(s) than fart around with machine shops and building engines that are (in my experience) Usually not machined or put together as well as the OEM stuff. Not to mention all the down time and cost.

Instead of building a block that will last a long time... Why not keep the setup simple and cheap and let a big turbo(s) do the work. If the engine lets go, have a spare stock long block sitting there waiting. Build the turbo kit in a way that makes for easy 4 engine removal. I can literally have my engine and trans out in under 4 hours. (and I didn't particularly set it up for quick removal) Engines are the cheap part these days. If the tune is "on", you shouldn't be burning through them. And if the tune is "off", the big $ motor will torch itself as well.

Also in my experience, things go wrong when racing, period. Doesn't matter if you have a $10k long block or a $500 long block. You'll get bad fuel, an injector will clog, a spring will break etc... And for the average guy just playing and not racing competitively... I'd rather destroy a "cheap" long block and replace it. Hell SBE 4.8's are making 1200-1300 hp these days with a cam and untouched heads. Running 7's at 40+ lbs of boost. I'm not suggesting you go buy a bunch of 4.8's... just that big boost is the cheap/easy way to power IMO. Which Is also why I favor lower compression motors with big power goals. If your engine only makes 400 chp NA, You'll have to run 30+lbs to get it to move. Which is why I don't like the idea of high compression ratios. Yet, if your making 650 hp NA, then you can hit your goals on low boost, then higher compression ratios are ok. It's a give an take kinda thing.

You may also consider a dual fuel setup, esp if your doing a dominator ECU. Run 16 injectors and pump/race gas. You'd be surprised how much money you save only using the race gas while under high boost. 5 gals last a long time! Also you don't need to just run the race gas or just run pump fuel. You can add a percentage of your total fueling. Say 15% c16 at 10-15lbs and 50% C16 at 20-25lbs. Alot of options out there!

 

Sorry....sir
Because only three of us in Taiwan swap Ls.
The three people in Taiwan swap LS, but only swap the inventory engine.
So I simply don't know where to go for answers.
Can only come here for help.

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I understand. Best option is to do what you can to get it running. As long as the bottom end is solid, you can always upgrade cam and heads as time and money allowed.

 

Don't try to reason with internet heroes. They heard a rumor that some magician made a million horsepower with pump gas and 50/1 compression. stick with something in the 9ish range and drive your car for years.