Which would be best a mild 408 or a radix. I know the radix would be the easiest to install but wouldn't a mild 408 be just as good or would the gas mileage really suck. Not trying to make a race truck but would like to have power when I put my foot in it. If I were to go 408 I would want something to drive about like stock,smaller cam and all.

 

If you don't intend to go with a big cam, then go Radix. A Radix'd 5.3 and a "mild" 408 would probably make similar power. You can build a budget 408 for roughly the same $$$ as a radix, but it won't make the power that a 408 with good heads and strong cam. Both options would respond well to good headers and other bolt ons. The radix will include tuning, injectors and upgraded fuel pump. Those are extras you'd need with the 408.

If you aren't concerned with a full bore race truck and just want a strong driver, the radix would be a good choice. There isn't anything wrong with wanting a 408 just so you can stay N/A either.

 

Can't go wrong with more cubes.....

 

It depends on your plans for the truck. I would have to agree with TEX on this one. I think the 408 will be close if not a little more than a Radix, and I am sure it will take alot more time to install.

Radix = one day HP (unless you are moregrip)

408 = buy it, have it built, take out the old motor, install the new one, have it tuned...yada yada.

I am sure most will disagree with me on this, but if you are looking for quick reliable HP, Radix is your answer.

 

For ease and hassle free power. You cant beat the Radix. It would probably be cheaper out the door. I think a 408 with mild cam and headers would be pretty sick. Check out the VicRed and 03 GMC video. 03GMC has a Radix and Vic has a cammed LS1, you would have about 62 more cubes. Of course last I heard 03GMC was using the stock pulley so he could pulley down for more power. I dont think you can lose either way. Can you do an engine swap?

 

Get the radix

 

Or you could buy a 408 from HPE for $3,899 with NO CORE charge, sell your 5.3, and use the $$ from selling your motor to buy fuel and tuning. They would end up being close to the same cost with the 408 probably being a bit cheaper. Also the HPE 408 also has a 2 year warranty if you don't use any power adders. It really comes down to if you want it to look/sound stock and be fast, or have blower whine, and not look stock under the hood. I like them both, and both would be a great choice, but if I were faced with it I would probably go 408 just because of more upgradability down the road. Just my $.02

Aaron

 

Are they really going for this cheap?

 

Yea. I saw that one day and was wondering why the hell it was so cheap.

 

They use good parts too, and offer a warranty, which is something that SLP doesn't offer with their 402, and SLP charges $100 more. I don't know why they are so cheap, so I won't ask