Looking for big block advice.

[87TBIguy]

Alright guys. So im looking for a little advice on what direction I should go.
Picked a 71' 454 this week. Knowing that the crank was broken. I was given another stock crank, a spare block, and a spare set of heads. Tore it down last night and found that its bored .030 over and has L2377 forged flat top pistons in it. Has oval port heads and a Performer 2.0 (I believe) intake.

This will be going in my mud/ trail truck. Truck has dana 60 front and 14 bolt with 4.56s
Running a 700r4 That I built. Should be able to take the abuse. Upgraded to 4l65e 5 pinion planetarys and upgraded sunshell, shift kit ect.

Looking for some advice as for what I should do to get the most out of this engine for my application. Mainly low end. Probly will not rev past 5k

Thanks.

 

[Irishman999]

The "mud trucks" around here are pretty much race cars, not even street legal anymore but I think I know what you mean by "mud truck".

Big blocks are all bottom end, they have plenty of grunt to break **** without much work. The performer manifold is good for torque, I would just order a cam advertised for trucks and towing and put together what you have.

 

[hirschdalechevy]

If you want real grunt go with a stroker kit , ( no subsitute for cube's) imo.

If you don't want to go that route you need to run your head number's to see what you have , if they are peanut ports you should file them in the nearest dumpster and get some head's , (big oval's). If you want the most out of your build I would run aluminum after market heads. There is lots of people that will say stock peanut heads make good power , (wrong) , for real power gains heads are they way to go. I have 1969 big oval , close chamber heads on my 454 in my crew cab right now and that motor dyno'ed at 465 hp and 525 tq.

Next , compression is power. You want to get the compression up with a piston , head combo that is still 92 octane friendly but your cam choice also plays a big part in that . The combo of piston's , head cc's , and cam dictate your cylinder pressure , higher = more power , lower = less power but you will reach a piont where you will not be pump gas friendly.Also you can get away with a bit more compression with aluminum heads.

Then you can get all the bolt on stuff after that , header's , intake , carb. , dist. , etc..... to match your build.

You will also need to find a good machine shop to do your work , there is so many machine shop's that dont know **** , so look out .

You can just throw together a motor and pick a cam and run it for cheap and a big block will have some grunt , but for any real power you should build it right and then hang on.

 

[87TBIguy]

Yeah I believe you are talking about megatrucks. Id like to make some good power, I mean I do have 42" tires to turn. Any suggestions on cranks? possibly stroker?

 

[87TBIguy]

Any suggestions on stroker kits? could I buy just a crank and rods and use the forged pistons I already have? I also have 2 head choices. Aftermarket is out of the question financially. I believe I have 046 heads ad not sure of the other set I have. Id like to use the intake I have as well, just for budget

 

[nvrenuf]

Carb or TBI ?

Also, did you mean 049 heads?

Flat tappet cam or roller?

 

[87TBIguy]

Carbed, Flat tappet.
Could have been 049 heads, I swear they said 046. But ill check both sets tonight.

 

[Irishman999]

The big block I just assembled for my truck is pretty much stock. Its bored .30 over, Sealed power Hypereutectic pistons, stock rods, stock crank, mild computerized engine friendly cam and roller lifter kit from comp, factory heads, Summit brand roller tip aluminum rockers, performer dual plane manifold and to top it off the factory TBI freshened up by our friend here Jims86.

This is in a half ton two wheel drive with weenie ass tires on it right now, I have to feather the throttle from a stop to keep from spinning the tires. I think a similar setup in a truck with 44's will be plenty.

 

[nvrenuf]

Carbed, Flat tappet.
Could have been 049 heads, I swear they said 046. But ill check both sets tonight.

The 049 and 781 castings are the preferred oval ports but they are open chamber so they won't make a lot of compression with flat tops. To put that into perspective, I'm running a small dome with 781's and have right at 9.5:1.

Not sure on the stroker cranks but I'd bet they will require a different piston.

 

[87TBIguy]

May stick with the stock crank ad rods if I can get away with it, since I have another stock crank to replace the broken one that was in it. Just unsure of how much it would be to buy a stroker crank vs having this stock one turned.

 

[nvrenuf]

Cast strokers are cheap, like less than $400! Of course, there's the domino effect so it may not be so cheap in the end. I was seriously considering one to build a 496 but just couldn't justify it since I had a NOS GM steel crank.

I went with a roller cam on my current motor but in the past I've used a Crane flat tappet #10307 with great success. Tons of bottom end and it runs out around 5500.

 

[87TBIguy]

Thoughts about Tbi on this engine? since my truck already has a tbi harness in in from the 350 that I pulled. Can I use my old throttle body an just but 454 injectors in it and get a tune? Just thinking tbi may be in my favor in the woods on inclines.
Also any chance 350 accessories will work with the big block?

 

[Irishman999]

Thoughts about Tbi on this engine? since my truck already has a tbi harness in in from the 350 that I pulled. Can I use my old throttle body an just but 454 injectors in it and get a tune? Just thinking tbi may be in my favor in the woods on inclines.
Also any chance 350 accessories will work with the big block?

The throttle bodies are actually different sizes, you can find a good used throttle body for cheap though. All the TBI stuff seems to interchange though, plugs, vacuum lines and sensors. TBI is good and consistant, I dont think a carb could do the same on inclines but a carb will flow way better.

 

[nvrenuf]

Yes
No
Maybe


Yes go TBI if you can. I would if I could but I just don't have the money for a kit.

No to the 350 throttle body, you'll need a 454 unit. You'll also need an adapter plug for either the tps or iac, I can't remember which. I think Howell makes the plug.

If you have a serpentine belt set up then yes you can use your brackets and accessories BUT you'll need adapter brackets from Kwik Performance. I did this on my motor, nice and clean set up.

 

[87TBIguy]

I think im gonna try to find a tbi just due to the terrain I will be in. And no serp belt either. I guess im SOL there and will have to source some parts for that. Reliable torque that's not going to cut out on me in the woods. I mean yes. I want power and all but toque is the priority.