a383z

iTrader: (2)

Ok I know this question has been brought up alot and alot of people have chimed in but i have a decision that needs to be made.

My current set up that was going back into the car

383 Super Ram D1X procharger - unfortunately guy who built it only built it to a 2 bolt main so blower will kill it quick

the Decision to go a bigger and badder SBC was thing a a 421 Dart and bolt the supercharger to that.

Or

6.0 Iron LSX retro the blower to fit the combination or buy a supercharger to go on top "root style"

I'm not positive the LSX combo will make more power but it will be more driveable power

the SBC combo should make almost 500 no problem and then a D1x blower on top that should be nasty.

Dont take into consideration cost of the rear or the transmission cause either way for this power level it has to be replaced.

Just dont think I can build a LSX combo that would match power wise for the same amount of money.

Please stay on topic so this doesnt get closed. Im ready to pull the trigger on a rebuild for my 91

Orr89RocZ

iTrader: (20)

Hp at the tires or at crank/motor?

Aftermarket block sbc like dart shp will run 1800 blueprinted and fully machined. It will hold 1000 hp. Don't need to go 421 but same price for 350 bore vs 400 so get some cubes. Only issue with this is you now need a crank for 2pc rear main seal. If your rods are good you can reuse but if not h-beams you should upgrade.

If you don't plan on goin over 800hp at motor then you could find a good 4 bolt block and swap in your assembly. If its forged and has good rods it be the cheapest bet and could hold it.

Lsx can also do well. Even stock 6.0 truck motors with mild cams respond well to boost. 8-10 psi can be 600 whp. Bottom end life is dependent on the tune but many have been up over 6-700 whp and living. You don't have to build it up unless you really want to for longevity and safety. Ported heads and a bigger cam makes it easier to make the power.

Cost of Lsx swap plus parts and blower conversion is gonna make for more expensive option for your goals. Granted the Lsx motor won't need the built bottom end but still need to swap it in. Lsx out the box has good potential and more with better parts but a sbc built right should easily make as much power. Especially dealing with 700-800 hp range.

If both are efi then properly tuned they should both drive well. Lsx may be more efficient due to its 15 deg heads and typically smaller cams to make same or similar power and rpm range compared to sbc.

a383z

iTrader: (2)

Thanks for the advice. I think I have to figure out how much power my sbc combo will make vs how much power the charged ls combo will make. The question seems to be cheaper or better drivability

paul_huryk

Why not just go big cube LSX (like a 454) and get 700hp+ on the motor alone? It will cost you in terms of all the parts, but you won't have to rely on a blower to make the power and will probably be easier to tune.

Orr89RocZ

iTrader: (20)

Thats definately doable. 600rwhp can be done in a 427 ls7 type build all motor or go abit more cubes for it. Definately possible...however it wont drive as streetable as a blower car with half the cam and heads and wont have ability to run a wide range of power increase you get the bug for more. You can have 600-800whp in the same motor setup with adjustments of boost and timing if you do it right. Tone it down on the street to enjoy and crank up at the track to set records

Jim85IROC

iTrader: (2)

Rather than find a 4 bolt block, why not just get your current blocked machined for splayed caps?