I think that would be the way to go. Buying used engines gives me the *******! WAY too many hackers out there!

 

Unless the plan is to go through the engine and add forged rods & pistons, heads and a cam.

A comment on the plan to use stock heads. It's been pointed out to me that an engine can produce power only if it can get air and gas into the chambers in large quantities. Stock heads won't allow enough air/gas to flow. Seems to me like staying with stock heads chokes the Radix. It's blowing but since the airways in the heads are relatively small the air/fuel can't get into the chamber to explode/make power.

Having had this pointed out to me I've revised my winter engine plan. Keeping my Radix is a given and then I think I'll find a salvage yard 6.0 (about 366 ci..... 6.0x61.023), maybe get 370 ci with a boreing to clean up the cyl walls in the salvage engine, and put then my $$$ into rods, pistone, heads and valvetrain.

I'd go with the stroker if I could get blownchevy to say whether the Radix will blow enough air to feed that much hole. Will it or won't it? That's what inquiring minds want to know!!

See... here's the deal. I don't know wtf I'm doing... I don't know SQUAT... so I need the guidance from those that do know what's up. Parish and Nelson say that the Radix won't blow enough to support 402 ci. But then I see Whitt1 with a Radix making 600 +rwhp and Blownchevy says in a post somewhere in this thread that the Radix is good for way more than 360 ci? Others say the Radix will feed 402 ci but it needs meth to reduce the heat from spinning that fast. Maybe I just need to stfu, DO IT, and experiment with different pulleys and see how much psi/boost I need to be a happy swede.

Bottom line for me is that I just can't stand the idea of the expense and work of building a forged 6.0 liter, then going to all the trouble of doing an engine AND trans swap, and then not getting the extra 40 ci and maybe 70 or 80 hp I could get by doing the stroker.

 

You can make big power with a 403 Radix setup,but you do it at the cost drivability and fuel economy.The big motor,big cam and heads setup has poor idle characteristics and will boost at part throttle due to low engine vacuum.The drivability is such that it is difficult to drive pull away from a stop without wheelspin and the average fuel economy is around 10 MPG[5 MPG if you stand on it].It makes big power that peaks at 5900 rpm and doesn't drop off until after 6600 rpm and revs freely to 7000rpm.The question that comes to mind is would you do it the same if you were to build it again?My answer is NO,there are both cheaper and better ways to go.As a max effort setup I could go with a turbo or larger capasity supercharger and add another 100+ hp or as a dailey driver I could stick with the Radix in a milder set up with a 100 hp less,with better fuel economy and drivability.The Radix is a great setup if you use it as intended,their more hp under the curve statement they make has merit as long as you have a relatively mild motor with good vacuum characteristics and a displacement that can be boosted without spinning the supercharger outside of it's normal operating range.My Tahoe is loud[it sets off car alarms as I drive by at 1/2 throttle or more]and it lopes so hard that I'm constantly asked what's under the hood.Every ricer on the planet wants to race[once],but it's not practical.

 

I got my 6.0 for $2000

I'll let you know if i can find another one.

BTW, when you swap two things you should DEFINATELY do BEFORE bolting on the intake manifold.

1. the line out the back, I think for the brake booster- yeah get that line on your new manifold first. It might not fit and you'll have to swap those end ports.

2. Fuel rails. Make sure yours are the same style (returnless vs return). rails easily swap but there is not manifold pressure port thing for the retunles rails. So if you have return and the new manifold does not- you will need to swap those from the manifold which consists of "break off with screwdriver, apply small amount of JBQuick to inside of plastic thing you broke off and swap.

 

jim s, stock 6.0 heads flow prety darn good from the factory and worked over heads are expensive. the general rule of thought is heads are one of the last things to worry about if you are boosted. if your going all out then sure, do the heads.

the cubes issue for the radix is along the same line of thinking, if your going all out go ahead and get the extra cubes, they will make it more fun to drive but you are not going to get 70hp.

when people ask me about heads and extra cubes i factor "bang for your buck" into my answer and in my opinion a camed 370ci(forged rods and pistons) is a great set up for the radix. you can more than double your investment and go with a 408 and heads and you might only gain a few hp and no extra reliability. i just dont see it as being worth it. ****some will disagree with me on this subject****

 

I agree with Parish. My motor set up is what he is describing and it is working out nicely.

 

Parish:
I in no way mean to say you dont know what you are talking about because clearly you do-

However I disagree with your "leaving the heads" comment. Here is my reasoning.

First:
The 6.0 heads were designed for an NA application. Sure you can boost them and make a ton of power, but you are really "fighting" the engine at that point. Why not correct them so that they are "designed" to do what you want. Boosted heads are very different than NA. they love exhuast. You really just do a lot of hogging because velocities aren't as important to you.

Second:
Reducing the intlet and exhuast restrictions make it so the blower doesn't have to work as hard AND so that more torque can be created through the powerband. this equates to less of a need to rev with the same power being developed. One could argue that huge heads that a blower wants will make it inefficient off boost and that could hurt you in daily driving- but its a big engine. I dont see any reason why you couldn't cruise around town without even dipping into the boost.

Lastly, polishing the combustion chambers can help reduce detonation. This is kind of debatable concidering the carbon build up that will occur, but when running something like water injection- it does a good job of clearing out that carbon.

Just my two.

If anyone is interested, one of my very good friends at school is persuing a masters degree in automotive systems. He does phenominal headwork and is beyond dirt cheap. I'm sure he would be willing to clean up those heads for you for lesss than you'd expect. He could probobly do an all out job for you as well, but i dont know how much time he has available.

He is pretty well known back in his hometown of huntsville and i've seen some of the stuff he does. I think he built the 1000rwhp TT mach one engine in FF&MM. His name is John Stimpson so you can do some research and if you're interested, I could get you a price.

 

I'm not wanting to spend the extra $$ on "Good" heads. I think the stockers would flow fine for what I am wanting. What I am wanting is this:
6.0L (LQ4)
Bored 30 just for a little more ci.
Forged internals so I can boost it to 10#'s and do a 50 to 75 shot from time to time.
If I can't find a builder who will do this engine for a reasonable price, I will do a stock 6.0, put my cam in, slap on the Radix and go.
That's all. I'm not trying to be the fastest Tahoe on the site or break into the 12's. I just want a daily driver that surprises people for how quick it is given its size and weight.

 

i was just trying to find a cheap 370 and i can't seem to. i dont get it. i thought you could get one for around $2500 and a 402/408 was at least $1000 more.

 

I KNOW! I've been looking. I can find a good deal on a 402! I would think a slightly bored, iron block 6L with forged goodies would be 2500-2800 and I'd be all over that.