AD resto-mod; Folks, can I ask your thoughts on Horsepower?

[torchlight]

Hey folks, would like to ask for a little discussion on horsepower/torque needs. It is time for me to start doing some preliminary planning regarding engine assembly, and I'd love to hear your thoughts and opinions. I don't have much experience with this kind of thing myself.

First a quick rundown of the truck/project. Truck is a 53 3100. Been in the shop for a few months now going for a full frame off rebuild. End result will keep body/interior mostly stock appearance - some updates, but nothing radically changing the character of the truck. Underneath, a complete modern update - ifs, 4-bar rear, disc brakes, new motor, auto transmission.

When finished, the truck will be babied a bit, but will not be a 'show queen.' Sure, will go to some shows, but will drive there, no trailers here. Truck will be stored during winter, but regularly driven during warm weather. Cruise nights and errands around town. Maybe a drive down to Iowa once in a while.

I don't see the truck ever being raced or going to a drag strip. So you can see it needs to have nice manners for cruising and driving around. However, I do want it to have some grunt under the hood. Would like to be able to get into the gas pedal and get pushed back in the drivers seat with a grin on my face.

Problem is, I've never really driven a higher-horsepower vehicle, so I don't have a sense for how much HP I should be targeting with the motor build. So here I am - what are your thoughts? With the weight of the AD truck, if this was your project, and you wanted it to have some real nice get-up-and-go without making it tough to handle on the street - what would you hope for on HP or torque numbers?

Oh, engine will start as an LS 5.3L with a carb intake. Transmission is TH350 with a Gear Vendors overdrive (don't want to have a tranny computer). Rear end is 9 inch Ford, but I haven't chosen a gear ratio yet. Will be 15 inch wheels with 30 inch tires.

Any input is appreciated, thanks!!
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[BlueJeep]

You asked for opinions, so here's mine. Go with a 5.3, but leave it injected and run the 4L60e behind it. It will be 300HP stock, plenty to put a grin on your face when you want to and tame enough to let the wife drive to the grocery store. Also, reliable, and capable of getting 20+ mpg. TH350 hasn't been the ideal tranny for a 'cruiser' for quite some time now, and the overdrive just adds complexity and cost that isn't necessary.

That's the route I'm going with on my build, and I have similar "requirements" to yours. In my 9" rear, I'm using 3.50 gears and 28" tires for mileage reasons.

[mr48chev]

I'd have to agree with Blue Jeep on this one. Swapping away from the fi and the trans that really works well behind it to regressive engineering just because isn't gong to be that great in the end.

And why spend and extra 4000 to do away with something that works and works well? That is if you can get a new Gear Vendors Overdrive, Carb and proper carb intake and the other pieces plus a built turbo 350 for 4k. Add to that you will have to cobble some sort of ignition together because you have removed the computer and FI that work with the stock igniton which doesn't have a distributor or provisions for a distributor as far as I can figure.
It doesn't really make sense performance wise or dollar wise. Plus you would be trading a potential 25 mpg for a potential 16/18 mpg if that.

[torchlight]

Can't do the factory efi. Silly as it sounds, I just can't stand the look of it. Will be 'efi,' but just something like FAST or MSD atomic on top of a carb intake.

As far as the transmission selection, that's driven by needing something that does not need a PCM and also dead bulletproof durable. Hard to beat a TH350 + GV for that. Read too much about questionable long term reliability on the 700r4 or 4L60. Would maybe consider 4L80E if I could get over the computer issue.
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[NEWFISHER]

I didn't read " saving money or mpg " in your response so I will give you my opinion on what I think you are looking for, then give you my opinion on what I would do if I had a fat pocket.
Build a 383, carb it and put a 700r4 behind it with a single wire 4th gear lock up, 3.73 with 30 inch tire.

Keep the 5.3/4l60 combo inject it, send the ecu out and delete the excess, reprogram it and use the 3 wire method. Run the 9 with 3:73....this will be the best all around power, reliability, economy, and less hassle in the long run. Remember, there is a reason ALL of the manufacturers have gone this way and its not all about emmissions ( you can delete it all), its reliability and having 300 hp at 20 mpg
.
The 700r4 is waaaay easier and cheaper than a 350/gearvendors unit

[mr48chev]

While trying to add up the cost of what you were wanting to do I came across this over on the square body forum that is worth checking out and has good info.

http://67-72chevytrucks.com/vboard/s...d.php?t=409490

I still think that spending upwards of 4k to spite something that works that is primarily going to be driven and maybe driven serious distances doesn't make a lot of sense.

Gear vendors od 2900 bucks their price.

A good rebuilt turbo 350 will run around 7 or 8 hundred if you order one from one of the name rebuilders or less if you do it yourself or get a buddy deal.

Edelbrock performer 7118. 719.95 http://www.summitracing.com/parts/ed...make/chevrolet Has timing module with it.

1406 carb 319.95 or 1411 carb for 339.95

That's just for the stuff to change from a fi 5.3 to a carbed 5.3 with turbo 350 and Gearvendors od not counting all the peripherals that get added on in any swap.

[BlueJeep]

Originally Posted by torchlight

Can't do the factory efi. Silly as it sounds, I just can't stand the look of it. Will be 'efi,' but just something like FAST or MSD atomic on top of a carb intake.

As far as the transmission selection, that's driven by needing something that does not need a PCM and also dead bulletproof durable. Hard to beat a TH350 + GV for that. Read too much about questionable long term reliability on the 700r4 or 4L60. Would maybe consider 4L80E if I could get over the computer issue.
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OK then, how about the FAST intake, really good looking in my opinion:


As for the transmission reliability comment, have you ever had a 4L60e? My last 2 Suburbans have had them, and my current Suburban has the updated version. They have provided trouble free driving for 210K miles, 150K miles, and currently 90K miles. Each has spent quite a bit of time towing a 3K pound trailer with a 5K pound Jeep on it through the mountain passes of Colorado with zero issues and only routine maintenance (transmission fluid and filter).

And finally, please don't take our comments as attacks on your ideas. You did ask for opinions, and some of us have some pretty strong ones!

[buggy5872]

For the fum smile on your face....stick with 3.73 gears and I would run a 700r4. I have a mild built 350 with a 700r4 and 3.73 dana 44 rear in my 59. It has plenty of power and fun factor. cruising down the highway I still get 16+ mpg if I keep my foot out of it.

[torchlight]

Originally Posted by BlueJeep

OK then, how about the FAST intake, really good looking in my opinion:


As for the transmission reliability comment, have you ever had a 4L60e? My last 2 Suburbans have had them, and my current Suburban has the updated version. They have provided trouble free driving for 210K miles, 150K miles, and currently 90K miles. Each has spent quite a bit of time towing a 3K pound trailer with a 5K pound Jeep on it through the mountain passes of Colorado with zero issues and only routine maintenance (transmission fluid and filter).

And finally, please don't take our comments as attacks on your ideas. You did ask for opinions, and some of us have some pretty strong ones!

In another vehicle the FAST intake or even the stock LS intake would be great, but the look is too 'modern' for this project. Purpose of going carb intake is to retain somewhat of the older style appearance in the engine bay. Will relocate the coil packs, use small-block style valve covers, etc. Sure is a nice looking efi setup though!!

Don't get too hung up on cost - willing to incur what costs are necessary to get exactly the right details.

Any other ideas on HP numbers?
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[mr48chev]

Your money have at it. Some things I do don't make sense to anyone else but myself either. The late engine it's self rather negates the old style look though no matter what you stick on top of it.

[BlueJeep]

So this is what you're looking for then:





300 - 350 HP should be plenty.

[torchlight]

Yes that's pretty much what I'm thinking! Great pictures.

From what I'm reading, might just be a new cam and springs onto the stock 5.3 and I'd be in business at about 350 HP.

Anyway, I'll also point out that the commentary has caused me to do some additional reading on transmission choices - I really do appreciate the input!
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[Speedbumpauto]

Just from reading between your lines, I think you want more toy and less practicality, within reason. So...400-450 HP and you can do that with the LS engines of larger displacement easily and even later on since they all fit in the same holes. I went more to the extreme on mine since I wanted the same kind of retro hot rod look but if doing it again, probably the bigger LS with forced induction. I also went with durability in a TH400 and a US Gear OD.(they don't make them any more) but doing it again, I'd lean toward the 4L80 with a stand alone. I didn't like the GV because they're only 22% OD and most factory OD's and the US Gear are 30%+. There are 4.11's in the 9 in mine but a 32" tire. Good luck and above all, have some fun with it!

[Amorget]

300-400 hp, somewhere in there is pretty awesome for just a driver.

I personally feel you are ridiculous not keeping the stock EFI.

[yossarian19]

The MSD Atomic kit dresses up the LS motors nicely.
If you want it to just look nice and don't mind a carb on top, get a 348 or 409 motor.
Carbing an LS is, well, kind of a waste. A lot of the benefits you get with an LS are the benefits you get with LS induction.
I mean, at 300 HP, do you really care that it's a 6 bolt main? Or that the heads can flow hella CFM?
For a driver... EFI is king. Has been since TPI in the 80s.

[OrrieG]

I have had street cars with big horsepower and cars with low horsepower. My experience has been the more your push it, the more time you spend messing with it to keep it running right. With todays engines you can get legitimate 300-350 hp with no problems once you get it set up right. When I was young I did not mind having to screw around with carbs and ignition in the middle of the dark and rain. Now that I am older it is nice to just go out jump in and drive. My Chevelle probably makes 300 HP with a TH350 and in 16 years as a DD has never let me down without a warning and that was expected, starter, fuel pump and battery.

All the engines I have are sbc, carburated, pre 74 with th350 trans just because I like the simplicity and in Idaho they are not smog tested. But I do find an LS with FI and an overdrive tranny attractive for a future project. I agree with those that say keep it like GM spent millions engineering it.

[1project2many]

When I was young I did not mind having to screw around with carbs and ignition in the middle of the dark and rain. Now that I am older it is nice to just go out jump in and drive.

What he said. I put EFI on my truck in the early '90s. I've made changes to the system over the years because I wanted to do it but the amount of adjusting and repair work has been minimal compared to carby systems.

300 - 350 hp makes a truck that can play with others without getting into too much trouble.

I think you're making a bunch of expense and work for yourself with the combination you've chosen. The THM 350 and 400 don't natively attach to the 5.3. You'll need an adapter to make that happen. And the 350 needs a mechanical connection to the throttle body so you may be playing games with cable length and brackets. Then there's the $3k to get the OD unit which would buy you a transmission with OD already incorporated plus a few cases of beer as well. Most of the LS style carbureted intakes are designed for racing which does not involve lots of time doing stop and go driving or part throttle operation so they don't have features designed to help heat and vaporize fuel at low speed and lower engine / ambient temps. Real street carby intakes are designed to prevent icing and aid in vaporization. And the aftermarket replacements aren't cheap. Finally, buying a computerized engine planning to throw out the computer, EFI, and trans controls only to buy an aftermarket computer and TBI, well, that seems like throwing out the baby with the bathwater. Why bother with the 5.3 at all?? The 5.3 isn't an all out power engine but it's a cheap engine that makes good power in factory trim. Undoing everything that makes it a good swap engine only to replace the programmed and working system with one you need to tune and adjust seems like a waste.

There's nothing wrong with using OE electronics. Avoid aftermarket computers.

4L80E is a very strong transmission with good long term durability. They'll see 300k miles in our vans without needing a rebuild primarily doing stop and go driving. Trans builders can make these transmissions into full manual shift units if you really want no electronics.

Finally, stock EFI manifold for 5.3 isn't the only choice for EFI.
Holley has a modular system that allows you to combine runners and plenums.
http://www.holley.com/types/LS Modular "Hi-Ram" EFI.asp
Edelbrock's Pro-Flo XT manifolds don't look anywhere near stock.

Just some thoughts.

[Atomsplitter]

It sounds to me that Torchlight has fat pockets and is only concerned about the LOOK of the engine! He doesn't care about gas mileage and he wants a retro look with modern EFI. Tell him what he wants to hear and make some suggestions related to his first post like Bluejeep did! I agree with the rest of you but it's his dime and he needs to be happy with it.

[solidaxel]

I think that is what happens when you live that far up North, too many months inside to think about what you MAY want.
Just keep us posted so we can see your progress.

[torchlight]

Just a quick update - I wanted you all to know that I really do value and appreciate all the feedback and commentary. In particular, it caused me to do some additional reading and research on the transmission choice, and have some additional conversation with the guys at the shop. I have changed my mind on the transmission choice, and today I ordered a 4L60E. So, thanks very much for the suggestion!

Sticking with the carb-style efi, though! That's one choice that is totally driven by looks, I'll readily admit.

[BlueJeep]

Sounds good, post up more pictures so we can see the progress!