Source
r/projectcar•
HunterRotten

350 V 454 (5.7 L vs 7.4 L) What should I do for my shortbed single cab C10?

I know there is quite a big difference between 5.7 L of displacement and 7.4 L of displacement. Is the 7.4 L all that much more worth it over the 5.7 L?

My dad and I have now been working on this truck(1978 GMC SWB) almost every weekend and are doing a complete frame-up restomod in our garage with what we have and what's available to us. I currently have the motor my truck came with and a bare block 4 bolt main 350. There's also the fact that my exhaust was made to bolt up to a very nice set of heddman ceramic coated headers for a small block. I don't think accommodating the pipes for a big block is much of an issue but I am out a set of nice headers.

I'm not too worried about gas mileage, this truck is not and probably will not ever be daily driven unless the weather is nice and the humidity is down. I don't see it getting more than 3,500 miles a year if that and I don't think it's going to haul much more than furniture occasionally.

The information given, what would you say would be worth my while for an engine? The current 2 bolt 350, a ground up built 4 bolt 350, or an upgraded 4 bolt 454?

I'm not looking to blow my socks off and be stupid fast, I just want some fun low-end torque and to be able to cruise along like a happy camper.

Posted Jan 31, 2017, 2:00 AM UTC

220
GMan509•

Only reason for a big block is style points or to get down the strip faster. Nothing sounds meaner than a cammed and straight piped big block, but a mild 350 is more than enough for a street truck

3
HunterRottenOP78 GMC swb, 63 Corvair•

My thoughts are it would be cheaper to get the 454 to where I want it then upgrade my current block or build a whole new engine. I already am in need of accessories like alternator and steering pump etc. I have aluminum v6 brackets I can adapt for the big block because Chevy is cool like that

1
GMan509•

It sounds like you already made your mind up. Junkyard build 454's can easily and cheaply make 500 ft/lbs of torque!

1
HunterRottenOP78 GMC swb, 63 Corvair•

I should add the truck is lowered with a tremec TKO 5 speed manual.

2
68-95-500•

The 350 can make 400 HP pretty easy. You are pretty hard pressed to make a big block make less than 400. A 454 makes 600 HP for the same effort as the 350

2
HunterRottenOP78 GMC swb, 63 Corvair•

I think a stock 454 made around 300 in 1980, my current 350 is tired and makes about 170 I'd say.

1
DZCreeper•

No point in wasting a good set of headers. Do a build with the 4 bolt.

2
shoelaces232•

Im going smallblock every time. Easier and cheaper to repair down the road

1
Boleo•

There are recipes for very affordable 350 builds with fairly easy ~350 hp on pump gas. Vortec heads, Holley/Edelbrock 600 cfm 4 barrel, Edelbrock Performer RPM intake manifold, appropriate Comp cam and valve springs for example. Stock/rebuilt everything else. If your 4 bolt block has hydraulic roller lifters those are an upgrade over flat.

The 454 will probably cost more with a higher power ceiling and another ~200 lbs.

1
Chaplian•

What are your power goals? A 4 bolt 350 can easily get 400whp with good heads, a cam, exhaust, and a decent carb.

Plus don't you have to put in bigger fuel lines for the 454?

Personally, I'd do 350. Add in some 3.73 rear gears, you'll have more than enough grunt.

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HunterRottenOP78 GMC swb, 63 Corvair•

I have a 3.42 rear end. I don't have too much of a power goal, 400 is plenty.

1
Chaplian•

Then you'll probably save a lot of dough by staying with the 350 imo.

1
Boleo•

Here's the thread I was thinking of. Sometimes selecting parts that all work well together can be tricky, but I think these build lists are some of the best bang for buck you'll find.

http://www.thirdgen.org/forums/engine-swap/569009-atillas-best-builds.html

1
Antoine_Jackson•

My buddy has a C10 with a 350 and one with 454, i can tell you right now your not gonna beat the sound of a 454 even with a mild cam, sounds mean, feels like it will tear you apart just sitting in it. Love rolling around and telling people its a 305

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DoOgSauce•

for a street truck, I would do a mild 454 and a 4 speed auto.

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HunterRottenOP78 GMC swb, 63 Corvair•

I've got a temec TKO 5 speed to go with it. I'm going to be building a 1982 2 bolt main 454*. I think it's going to be bored .060 over instead .030 over as a result of rust damage to the top of a cylinder wall. Going to go with Edelbrock performer top end with weiseco forged pistons. The stock cast crank and rods will be at the top end of the HP range they can handle but they can handle it up to about 6k rpm.

Right now I'm trying to sell stuff. I sold my 350 for $650. I bought the 454 + performer rpm intake for $725.

Now I have to try to sell a set of $600 headers, a NV3500 transmission, brand new machined and ready to go vortec heads for a 350, and a pool table.

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DoOgSauce•

You are moving right along! Why the TKO over an NV4500?

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HunterRottenOP78 GMC swb, 63 Corvair•

I've had the TKO for awhile and wanted to go a different route. If I could I'd probably get the T56 magnum or even the NV4500. But, since I have the TKO 500 and dropped good money on it, it's what I'm going to use.

I could always change it out later if I really had to but I doubt it as the TKO 500 is entirely rebuildable. Hopefully I don't regret it with a 454 torque monster but I have had the holes drilled and all my drivetrain components made up for the 100% perfect and optimum running setup.

Wooooow, I just realized I told you I was going to build a 350. Sorry. I am building the 454.

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DoOgSauce•

No need to apologize. I gathered you were building the big block from your earlier post, that is why i asked about the tko. If it is a built TKO, it should be ok behind the 454. I'd still be tempted to trade it for the truck trans though because my right foot is heavy.

1