87 R10. 383 or built TBI block

[UATahoe]

Alright, i have decided to retire the stock 350 motor in my 87 R10. I know it at least has 192K miles might even be 292k. First off, i wil be keeping the TBI system and have been working with Brian at Harris Performance on all of the necessary upgrades for that piece. My only dilemma is whether to go with a 383 or a TBI block with Vortec heads. The 383 setup is going to be right at $2900 oil pan to intake. Would be completely ready to go. I have also found an old TBI Block and Vortec heads locally from a family member. Block is completely machined and rebuilt, heads are totally rebuilt as well. All receipts for machine work available and the shops used are really good. Price on that would be $1000 with a lot of extras included that i could probably sell and get some money back on. Only thing needed would be a cam and intake (priced out at $400 total).

So, my questions is, is it worth the extra gains to spend $2900 on the 383 or would it be better to stick with the TBI Block/Vortec HEads combo for $1400?

I have been told the 383 will be around 360hp/420tq and the TBI/Vortec will be around 330hp/380tq.

One other note, i wont do a whole lot of towing and even if i did, it would be with other vehicles. This is mainly just a cruiser that i love to drive.

I am open to any and all comments here. Let me know what you guys think. Thanks!

[Desert1957]

There is nothing better while towing then "TORQUE" the more the better. People get all wrapped up on dyno numbers about "Peak Horsepower" when its a nice smooth torque curve that makes an engine feel strong.

Go with the 383 , might want to re look at the stock style TBI, not sure it will feed a healthy 383 without some modifications.

Desert

[UATahoe]

I am definitely upgrading the stock TBI with a bored throttle body and better fuel pumps computer upgrade etc. Main reason for the question, i just dont know if its worth the extra $1500 for the 383. At the end of the day, both are basically brand new motors and arent too terribly far apart on performance. Especially considering that both are basically doubling the power output of the stock motor. Both engines will have plenty of power for me.

[bk2life]

TBI/Vortec will be around 330hp/380tq.
id be leary of this claim

[bnoon]

Personally, I'd add a 3rd option. Given the info you have listed, I'd add a Scat crank and KB pistons to the Vortec setup you mentioned and have a 383 Vortec for several hundred less than the other 383 you priced out. As long as Harris Performance has the tricky TBI tuning figured out GO BIGGER! LOL!

[mooseknuckles]

.....LS swap.

[king-918]

383 with vortec heads, and roller block
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[king-918]

Oh yeah and carb or true fuel injection
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[UATahoe]

To clairfy on those numbers for the TBI, this would be with vortec heads and a Lunati Roller cam. I have all of the parts to convert the TBI block over to a roller setup. Also would utilize a better intake with the bored TBI. It wouldnt just be heads. The 330hp claim doesnt seem too far fetched to me really.

The idea of continuing the build on the TBI/Vortec motor is appealing though and making it into a 383.

[Low84]

Even though the peak numbers are close to each other it doesn't mean the engines will perform at the near the same level. The 383 should reach it's numbers earlier in the rpm range and they usually have a lot of power under the power band.

I see you saying or the TBI block. Does that mean that the 383 is going to be based off an older 350 block?


I'm very skeptical on that TBI working though, keep us updated. I'd love to see it happen with either option.

[UATahoe]

The 383 is a vortec block and vortec heads.

[king-918]

Why tbi?
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[UATahoe]

Really just for the novelty of keeping it. Only year they offered fuel injection for the squares. Plus, I am not looking to make crazy amounts of power and I have been told I should be fine wih the right upgrades to the fuel system.
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[school boy]

Originally Posted by UATahoe

Really just for the novelty of keeping it. Only year they offered fuel injection for the squares. Plus, I am not looking to make crazy amounts of power and I have been told I should be fine wih the right upgrades to the fuel system.
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my 86 has a tbi, was it just an option in 86?

[Pyrotechnic]

The TBI will work fine, it's a just a matter of having injectors capable of feeding the engine and being able to tune the computer correctly.

As for the Roller 350 with Vortec heads from the family member, was anything special done to the Vortec heads? Reason I ask is that in stock form they can't handle much of a cam. The valve guides need to be machined down, and it's a good idea to run screw in studs with guide plates. Keep in mind, you will also need run springs that will work with your cam. Don't forget a good set of hardened push rods too that are the correct length. What I'm getting at is that there may be some hidden costs into getting this motor to work for you that you haven't thought of.

If you do decide to build a 383, have it built with a roller cam TBI block. This is what I did and I'm very happy with it, primarily because I don't have to do anything special with the engine oil to get a flat tappet cam to survive. The extra power is nice too.

[Richardman1992]

I vote vortec 383 with roller cam and tbi. Have you looked into ebl tuning? From dynamic efi. Doober on fullsize chevy has an ebl tuned vortec 383 with a cam in his 92? I think truck.
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[UATahoe]

Heads are completely reworked with new valves, upgraded valve springs and new pushrods.

I plan on using the upgraded Police car TBI 350 injectors or 454 injectors. One of the two. And i currently have the gm performance parts roller lifter kit to convert the block over to the roller cam.

[INSIDIOUS '86]

Tbi was designed for mileage and emissions. Sure you can get it to work but are you prepared to spend half as much on your engine to do it? The vortec 350 is a great engine esp with a roller cam. A 264 comp cam and pocket port heads will do 350 hp easy and be a great everyday. A 383 will tap out vortec heads sooner since it will draw max flow sooner it will be like the 350 but bigger. Bigger power bigger thirst bigger speed an will daily fine. But with stronger heads will be a force of an engine.

If your using the same cam on both the 383 will have barely an advantage
Tbi doesn't like big cams either. It's the number one enemy of tbi
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[UATahoe]

Keeping the TBI is definitely costly. about 350 bucks for all the parts (bored tbi, new injectors, tbi adapter) and then of course the computer programming isnt cheap either. I just didnt want to lose the economy of the TBI.

[INSIDIOUS '86]

Going bigger will always lose economy 1/2lb fuel is one hp per hour.
You may be money ahead doing a mpfi or a tpi

Sounds like a vortec 350 will be a good match. As well as balanced gears and overdrive you should be able to drive it daily and have fun when you want. While not a Prius it won't be a racecar at either
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[UATahoe]

Exactly what i was thinking. AS long as it stays in the 15-20 mpg range i am good. LOL. Hey, good gas mileage is a relative term. And i think the 350 will produce plenty of power, especially over the stock 350. Should be a night and day difference in the two.

[UATahoe]

What gear ratio would work best? I am not even sure what is in the truck now honestly.

[INSIDIOUS '86]

Depends if on your trans and where you drive the most city or highway. 3.42 gears are great all around gear 308s seem just a lil to tall geared so I you want a lil more mileage and some performance 3:23 is a great ratio
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[huahuamick]

TBI/Vortec will be around 330hp/380tq.

[BigBlocksRule]

Before you spend the coin having a stock TBI bored and rebuilt, find one off of a 454 and use a simple rebuild kit. You'll need to swap a couple of plug ends (IAC and one other), but you'll have all the airflow you need and bigger injectors for less money.