So I hear about all of the after market support for an LS engine. If you did an engine swap what other alterations would you make to a 5.3 to add horsepower and/or torque.and how much do you think it would add to cost of engine if being professionally installed (i.e. I ain't doing the install).

 

depends on your budget....

intake,long tube headers,exhaust and custom tune at a minimum......This would give you close to 375hp (flywheel)

you could do a set of heads/cam on top of all of this and you would get another 75+hp

If it were me I would try and find a used magnacharger TVS1900 for a silverado and make it fit. Depending on the pulley and tune you could get an easy 450+ hp (flywheel) and be dead nutz reliable.

 

So who makes long tube headers for the 5.3 JK conversion?

thanks
GW

 

There are many ways to improve an LS. The best bet for real gains without breaking the bank, are a decent set of CNC ported 243 or 799 heads and a cam suited for low end torque. I'd also recommend running an untouched LS6 intake as that will help performance down low when coupled with good flowing heads. Depending on where your engine came from, you probably already have the 799's. Of course all of this would have to come together with a good tune.

Send me a pm and I can give you some contacts to steer you in the right direction. This is what I do for a living

 

These are solely my opinions, i am not an expert and do not claim to be. I am already doing this mod which is in progress in another thread and these are my plans. Everyone has their own ideas for the ideal engine combos and how much power they WANT, not how much they NEED. Assess how much power u NEED. Determine what u really plan on usin the jeep for. High hp is only needed on highway acceleration or in tire spinning mud. Rock crawling requires a controlled throttle in mid to low rpm, hp is made from gearing, not necessarily high engine speeds (having built several vehicles, i was able to really able to narrow down my desired results and uses for this one-i want a jeep to cruise around town in at max speeds of 55-65 mph highway speeds and some occational mild to medium rock crawling. I will never touch mud if it is avoidable-i dont like the cleanup afterwards. I know, im lazy)

The best mods u can do for the 5.3 swap is do it right from the beginning. A stock 5.3 is outputing 325-350 hp. That is pretty decent power for this jeep. Not overwhelming but like it should have come stock. The ls3 would be awesome but can be cost prohibitive and requires more parts and effort to go that route. It requires more cooling, heavier duty driveshafts and larger exhaust than the 5.3 (and possibly more fuel delivery than the stock jk pump can put out when motor is at high rpm's). These are the reasons i went 5.3. If u start adding performance parts to the 5.3, at some point u would have been better off going bigger engine.

Mate it to the 6 spd auto so that u have more gears to spread the rpm band accross and be more efficient with the power that u have.

Install gearing in the axle that compliments the tire size selected and so that when the LS motor is in final gear at highway speeds it is rolling enough rpms to be efficient. (Look up total final drive gear output from the donor vehicle and make ur total final drive output match it and then choose a gear set one step numerically higher than the donor vehicle would have come from to give an improved feel of power with a slight reduction in top speed. remember, donor vehicle was not setup to be a good balance of power to mpg. It was setup to be fuel efficient while not letting the horsepower suck-they have CAFE standards to satisfy-we dont.). Be sure to have the gm computer updated to the final drive ratio so that the gm computer and the jeep computer both display same speeds or the gm trans will be shifting at wrong times, possibly causing damage.

Getting an engine that is an aluminum block will save weight (about 100lbs removed from the upper half of jeep will really improve its center of gravity compared to a cast iron block and improve its acceleration due to same hp but less weight to push.)

Reduce weight of total vehicle-use aluminum bumpers and armor, lighter weight but desired size tires, relocate the evap vs putting a skid on it, etc. these things affect the power feel of jeep all the time because everywhere u go u tote all that weight. Determine what u can do without can be alot cheaper than increasing the hp to compensate for super heavy items loaded on and in jeep.