Jegs has a kit to convert an LT1 to an LT4. Its about 2.4k and says it will take me to 330 hp. It has peaked my interest. is something like this a good idea?

 

only if you think 55hp is worth 2400

 

you can get more horse by puting headers, bigger exhaust and a bigger throttle body. throw a coldair intake into the mix and you'll see a noticible differance, and if you can flash your ecm with a racing setup.

 

The LT4 conversion isn't worth the money, the parts are pricey because they have "GM Performance Parts" stamped on the side of them. You can get components that get you much more HP for the same price, if not less. The money is really in the heads, and if you're going to spend $2K on heads you would be much better off with a nice set of AFR heads.

Mustangfighter: Just for future reference, unless the LT1 has had upgrades to it's heads or cam you won't get any power from a new throttle body. To actually use the flow of a 52mm TB you need to be putting down over 310 or so RWHP, and for a 58mm TB you need to be putting down somewhere around 350 RWHP, otherwise the TB can outflow the motor. I would always suggest getting a CAI before a new TB.

 

Pull the stock heads and get them reworked and ported and polished. $600-$800 depending on where you get them done. Drop in a larger cam for about $250-$300. Custom tune (madmike or pcmforless) $175-$250 and you can probably achive 350-400 horse if you have all the bolts on's too. Which puts you around $1350-$1500 spent. A lot les than $2400+!! Of course this is just an estemate but you get the idea.

 

^^^supporting mods with all that will get you to the 2400, but a definite better route to go!

 

Yeah he’ll still do better than 55 extra hp.

 

Keep in mind that we're talking crank HP as well, and that 330 HP that they get out of those conversion kits is on an engine dyno not running any accessories in near perfect conditions.

 

the only LT4 kit i see in Jegs is the kit that comes with the Edelbrock version of the LT4 head , the Edelbrock LT4 AIr Gap intake and a GM Hot Cam kit and a full gasket package for $2,800 . if this kit makes the power GM claims a LT4 with Hot Cam kit will make , it should make 425 hp , not 330. i would like to see a LT4 with the Hot Cam on the dyno to see if it actually makes the power they advertise.

 

Like I stated previously, the 425 Crank HP is achieved under near perfect conditions where the motor isn't running any peripherals except a water pump and it has dyno headers etc. to inflate the numbers. The differences between the LT4 cam and the LT4 hotcam are not nearly enough to net almost 100 HP under normal driving conditions.