GM crate engines?

[Christian Steffen]

That definitely makes a difference, if you have no plans to modify it a warranty is awful appealing.

 

[PlayingWithTBI]

I bet you get a 12 month, 12000 mile warranty in non-approved applications, such as stuffing a "HD" 3/4 ton long-block into a half-ton truck.

Good call! I wouldn't have thought for a minute that's their policy.

 

[Tachyon]

The warranty was part of what flipped me to the GMPP HT383E myself. Sure. I could have built something cheaper but a warranty that I can have honoured at any GM dealer anywhere? What's that worth?
IMO it was worth more than the cost difference between a home brew small block and the HT383E. Of course not everyone has the same priorities. However my reasoning was much like the OP's. I wasn't looking to build a hot rod. I was looking to take a truck I love and give it a new drivetrain so I could continue to enjoy it daily and reliably for years to come. The extra power, towing capability, strength, and reliability of the HT383E over the stock engine was just gravy.
I have not once regretted the decision. My only regret in the whole process was not replacing the OEM fuel injection spider with the newer upgraded part at the same time. Mostly because no one asked or told me it was an option.

 

[alpinecrick]

I don't think that is the case. GM says you can run the HT383 on the stock tune. You can change your exhaust without a tune.

Optimizing the tuning helps even on a stock engine, but it is not required. Definitely not required for the possible 5-10 cfm difference (if that) in flow on the exhaust side of HD vs SD heads.

That's good to hear. I don't know why installation of a 4 bolt into a 1500 truck would be that different to "confuse" the factory tune. There is a certain amount of latitude in the factory ECM tune....I think.....

 

[Schurkey]

I don't know why installation of a 4 bolt into a 1500 truck would be that different to "confuse" the factory tune. There is a certain amount of latitude in the factory ECM tune....I think.....

There's no sensor to tell the computer how many main bolts there are.

 

[alpinecrick]

There's no sensor to tell the computer how many main bolts there are.

That much I know.......then again, computers CAN count, ya' know.......

 

[GregB]

I'm still on the fence trying to decide which engine to get for my Tahoe. The 2 bolt or 4 bolt main or the 383E which I initially wanted but am having trouble justifying the cost difference of the 383..

 

[Tachyon]

You do not require a tune for the HT383E swap, it's just recommended.
No it's not a straight swap in the sense of a tune. The HT383E does have a longer stroke and slightly stronger cam which means more airflow. I'd also recommend a free flowing exhaust system upgrade. Overall that means a good bit more airflow, which means you need a tune to provide more fuel to match. It does run fine on the stock tune, but it comes alive with an upgraded tune.

 

[Christian Steffen]

If you spend 5k on a motor, don't skimp on the couple hundred dollars for a tune..

 

[HawkDsl]

TBI can take the 383, and self adjust just fine.. I imagine vortec computer can do the same. You don't need a tune.. your computers do that on their own. That's why you have an O2 sensor. The "tune" part, is telling the computer to handle what it sees differently. More timing, more fuel, etc. The factory original tune is the "safe" tune. GM does that for warranty reasons, and frankly, extends the life of your motor. There's allot of "performance" left on the table with all the C/K motors. Anyway, so long as your injectors and fuel pressure can keep up, the computer wont get scared.