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Big block newb with a low milage 454 Advice please

original balzer

original balzer

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This 78 truck I have as a donor for my project has a new 454 in it. Well its slightly used. The truck has the 400 in the grill so I assume it was originally a 396 truck. The guy I got it from said he had the local GMC dealer put in a new engine and trans. He then drove it for 1 hunting season then got himself a newer truck and parked this one. The engine is obviously fairly new in appearance. It has 7.4L cast into the side of the block. Assumption #2, its probably a 1970's stock spec 454.

It has a crap edelbrock carb on it. I will either swap on a 795 cfm q-jet OR I have the possibility of a holley projection 4 unit that I might try to make work. The guy I got the FI from told me it ran too rich on his mild 400 pontiac and he never could get it to run right but I am sure there has to be a way to make it work.

I want a little more but I dont need serious power. A mild big block should do me just fine.

So would a cam swap be worth my time? I know there are different head port shapes but have no idea what I have. Is that something I should even be concerned with? Or should I just put a nice intake on it and try to make the projection4 work?
ALSO just for giggles I have a set or CBB roller rockers and the support bar thingy.... is that something I can use? I dont even remember the brand name. I do remember they are slightly used on a drag race engine that lost the bottom end after just a few runs (NO2 was not his friend)
 
They weren't using 396's (or 402's) in '78. It probably left the factory with a 400 SBC. You couldn't get a BBC in a 4x4 until a few years later.

Martin
 
The block and heads will have casting numbers on them, which would tell us a lot more about what you have and what it can or can't do.

-- A
 
dremu said:
The block and heads will have casting numbers on them, which would tell us a lot more about what you have and what it can or can't do.

-- A
Click to expand...


Block casting number is 14015445
Head casting number is 14081045

all I found is 1978 to 1990 production years

Oh and there is no stamped number on the flat spot in front of the passenger side head. no partial vin #
 
The block is a good, average piece. I'm using that same block in my blazer, it could be either 2 or 4 bolt main (mine is 4) but you'll have to pull the oil pan or timing cover to see.

I don't recognize the head number and my book is at home. :dunno:
 
I'd say get it running and see how you like it. Go from there. The pro jection would be nice to have. He was doing something wrong if it didn't run right. Sensor was off or something. Bad o2. Maybe needed a heated one depending on where he had it. As far as cam goes with the injection ive heard they dont like a wild cam so close to stock or a slightly bigger one would work. Could be any number of things. If it was rich on his it should run better on yours either way. That engine is Gona like a lot of fuel. I know every guy has his likes but my edeljunk works good for me and have never had a problem. Correct jets and spring needle and seats with it set up right does wonders. Ive only run small blocks but im a creature of habbit and dont like change. Congrats on the new find. :thumb:
 
Details for 14081045
Manufacturer Chevrolet
Category Cylinder Heads
Type Big Block V8
Date 1978-1987
Notes oval port, open chamber, 454

From what I read those heads are good in stock form and don't like much more than a stock or rv type cam. They are low compression heads at 7.5-8.5/1 depending on the pistons used. But stock they will produce around 300 hp and 400 lbft of torque with what you have on there now.
 
So the heads restrict it to lower RPM performance correct?

would this combination or something similar be too much? Edelbrock for quick example

Performer-Plus Camshaft KitChevy 396/427/454
.500''/.500'' Lift
292°/302° Adv. Duration
Idle-5500 RPM Range

Performer 2-O Intake Manifold BB-Chevy 396-502ci - Oval Port
4-bbl Spread-Bore Carb Flange (with EGR)
Idle-5500 RPM Range


sub 800cfm carb


set of headers


Basically my question is, Can I get close to 500ftlbs of torque under 4000rpm, for under $1000?
Just web searching it looks like most truck 454's from 78-90 are in the mid 300's for torque. I am assuming stock cams and intakes are really crappy as most small blocks suffer from this in stock form. Im not even sure if the headers would be necessary would the engine flow enough to even bother with headers?
 
A stock 454 crate motor picks up something like 50Lb/Ft of torque with a set of longtube headers.

My recollection is that the exhaust side of the motor is the worst part of the stock design, so the headers really wake things up nicely. Dollar for dollar, I don't think there's anything as effective on a BBC as a set of headers.


-G
 
Well I cant be certain, but from that Greg, I would think I could get real close to 500ftlb of torque with $1000 and half a days work. Now would long tubes or tri-y's be better? if I remember correctly tri-y's help keep the tq lower in the rpms right? I havent looked but I would imagine tri-ys are more expencive are they worth the extra money?

Im not sure what will get built a trazer or a pickup or whatever. But I might as well try to get the most bang for the buck with the 454, regardless of what it ends up in.
 
I've only seen one dyno test of Tri-Y's vs. long tubes, and I remember the Tri-Y's losing everywhere.

Some of the effectiveness of various designs is dependent on the motor itself, but barring any concrete evidence to the contrary, I'd just stick with long tubes.

I know a lot of people love Tri-Y's, I just haven't seen the dyno tests to back up the claims.
 
dyeager535 said:
I've only seen one dyno test of Tri-Y's vs. long tubes, and I remember the Tri-Y's losing everywhere.

Some of the effectiveness of various designs is dependent on the motor itself, but barring any concrete evidence to the contrary, I'd just stick with long tubes.

I know a lot of people love Tri-Y's, I just haven't seen the dyno tests to back up the claims.
Click to expand...

My experience with tri-y's is with a SB. I like them with a stick when opperating at low rpm at partial throttle. Long tubes worked better under full throttle and with a auto under all conditions. Just my 2 cents.
 
Looks to be what you listed would work and get you closer to where you want to be. I like long tube headers myself. The big block will have more problems with your shackles though. Mine I had to heat up and bend in a lil torward the oil pan to keep away from them. You will have a more constant torque curve with them as we'll. that combo could get you into the high 300s hp and 500 torque. You may lose some low end torque but a big block in a trazer won't need a ton to get moving. Clocking the cam 10 degrees I've seen will help flow better as well with a bigger cam.
 
original balzer said:
Well I cant be certain, but from that Greg, I would think I could get real close to 500ftlb of torque with $1000 and half a days work. Now would long tubes or tri-y's be better? if I remember correctly tri-y's help keep the tq lower in the rpms right? I havent looked but I would imagine tri-ys are more expencive are they worth the extra money?

Im not sure what will get built a trazer or a pickup or whatever. But I might as well try to get the most bang for the buck with the 454, regardless of what it ends up in.
Click to expand...
OKAY this is so random, I joined this forum ONLY because of your K1500, I have the same truck, am looking to build it out, potentially long travel, MAN I have to know what you did to that truck it looks so clean! If you’re still on here, could you just tell me, front kit, wheel/tire set up? Thanks so much! I’ve been scouring, there’s not much I like, and your truck cruuUuushes it
 
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