built 406 or mild 350 w/whipple

[b454rat]

I don't have a build thread or signature or anything like that. I have a 96 4 door lifted Yukon that has 68k with a Whipple supercharger. I bought it dirt cheap, knowing it needed motor/trans. I bought one with 138k, ran friggin' great, and was impressed with what a stock motor would do with the 'charger, trans was the biggest issue, needs to shift firmer. Anywho, the motor went again, dunno why, developed a rod knock. Buddy has a motor from a 1999 crew cab, supposedly a 4 bolt. I also have a 98 4 door tahoe 2wd that I lowered little bit. That runs great, even with 205k on the clock, I want to build a motor for each of them, but not sure what way to go. I have a 406 block ready to go, just need rotating assembly. I also have a Ramjet intake. My thinking was build the 406 with the Ramjet for the Tahoe, and making a 383 for the Yukon, leaving the charger. But I don't think there is a whole lot to do with the charger to get more out of it, the bigger the motor the less boost it will make. Then i found a complete 98 truck with a running driving 454, trans has issues but that's not a big deal. I'd put the 454 in the Yukon, since it's lifted, but gonna be doing an SAS on it, prolly next summer when the garage goes up and have a concrete floor. Which leaves me to figure what to do with the whipple. I was advised not to put it on the 406, even tho won't make much boost, and would be tough to hook up with the Ramjet. Would look cool as hell under the hood tho. **** part is I'd have to sell something to get the 454, current job don't pay **** to save enough. But really don't wanna part with the charger. So, put the 454 in the Yukon, or keep the whipple? Or build the 406/Ramjet for the Yukon and put the 454 in the Tahoe? Hate being broke....

 

[b454rat]

Pics of the 2

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[618 Syndicate]

Dope rides...
I know you didn't ask, but I think you need to figure out why you've broke two motors with the whipple before you put it on another one. My guess is lack of proper fueling.
If you're gonna do a motor swap, why not do an LS? Cheap and easy upgrades....

 

[b454rat]

I bought the yukon w/whipple with a bad engine/trans. Story goes, bought it off a girl who beat the **** outta it. We all know how weak 4L60s are, being lifted with lil bigger tires, than add the whipple, know wonder they don't last. The trans only had 2nd gear supposedly, and when someone drove it they didn't know that, and overrevved or did something to the motor, and was knocking like crazy. I have always ran 93 in it, so dunno why current motor went. I'm thinking it might have an ECM flash or maybe a pully swap. Always had oil, and good pressure. I'm not really concerned bout why the motor went, I don't know the history of the motor. It ran good, but might have not been maintained very well. If I build a motor it will built to handle the whipple.

 

[b454rat]

Oh and absolutely no desire in an LS swap. Been looking into it and way too much bullshit to deal with. I can get any of them dirt cheap, but I can build an engine cheaper than the LS route. And don't really like how they make their power way hi in the RPM range. Great for a light car/truck, but not for a heavy ass 4wd.

 

[618 Syndicate]

When you add boost to a stock motor there are things you need to do to make it live. If your current setup has killed 2 motors, I'd be interested in knowing exactly why, especially if I was planning on using it still. That's just me though.
I disagree completely about an LS not making power down low, they're in literally over a million heavy ass trucks!
Now, your lack of desire to build one and ability to do a small block cheaper is personal choice, and I totally get that, but the LS family are very capable platforms.
A big block in that Yukon would be cool, a blower on top of it even cooler!

 

[b454rat]

Whipple says to use a "stock" motor, so that's why I think there's something else going on. I also forgot to mention both vehicles will get the 0411 ECM, which would help in the fueling issues, since the "whippltronics" is garbage. I have an early whipple, and uses a glorified drip for fueling, so it could very well be the issue as to why this motor went.

I have friends with 4.8s, 5.3 and 6.0s. I'm not impressed with any of them. Granted they are all stock, but I had an all stock Vortec 454 that would smoke the tires just nailin' the gas. I'm not 100% out on the LS, I'm doing some reading as we speak. But I've always been a big block guy (hence my s/n) and wish I never sold the ones I've had. One other thing bout LS's don't know **** bout em.....

 

[618 Syndicate]

There's a reason GM dropped the 8.1, and it's because the 6 liter makes similar enough power that it became irrelevant. LS based engines are cheap, efficient, and we'll supported by the aftermarket.
You can certainly make power with a big block, but you don't need one to make big power like back in the day.
Technology bro....

 

[b454rat]

No way a 6.0 is gonna make 8.1 torque. Not without some work. I thought about the 8.1, but there ain't **** for support for those. $700 for a carb'd intake. But supposedly with a cam n a tune can get over 500 horses with one. After I lasted posted I checked parts for rebuilding either, and they were bout the same. But I know I can get a **** ton more torque out of the big block than a 6.0, and at a reasonable RPM. I rarely drive over 4500rpm, seems to where an LS starts to make power. The fueling/intake on a big block is better than the small blocks, at least you can upgrade the injectors. I'd be going with the 0411 at some point, who knows what I'll do later down the road.

But I think gonna put the 406 in 2wd Tahoe, along with the Ramjet intake. Found a build that made 425/525 with a pretty mild cam. And if i can get the 454 truck I found, put that in the Yukon. Maybe save the whipple and other 2 vortecs I have for a future build. Wifey wants an old school car, 55-57 Chevy, if we can find a decent 4 door without giving up first born....

 

[Schurkey]

Are you SURE you've got a rod knock?

I popped a head gasket on my TBI. Looked around for a Vortec short block to get the roller cam system. The short-block I bought came out of the vehicle because it had a "rod knock".

Turns out, the flexplate was broken. Common as dirt on the one-piece-seal engines.