The Stovebolt Site Forums The Shop Area The HiPo Shop building a 427 BB for my 69

hi there
I was wondering if anybody has built some Big Block Chevys befor
I am working on a 427 made with 366 forged steel crank,and a newer 454 short block and 366 truck heads with ports smothed and polished
I was wondering what work will have to be done to crank, and what would be good camshaft grind to take advatage of short stroke and small ports, to make qick reving low end tourq but not lose normal: mid to top end power

I'm not a big block expert, so I've little to offer in the way of help.

But if I remember right the deck height on a 366 is higher than the car motors. I presume either the rods are special length, or the wrist pin hole is at a different height.

So I'm wondering what combination of rods and pistons you are using in this motor?

Second question, if the deck height is higher, then the intake manifold is different. What intake will you be using with the 366 heads?

Maybe I don't remember correctly, and there is no deck height issue. If so, straighten me out. Otherwise, I'm curious what combination of pieces are you using?

yes the 366 and 427 block is taller than 396-454 but only the block
the head are basicly the same as car head expt smaller port with higher volicity wich makes lots more low end tourq
and the orgnl pistons in the 366 are a 4 ring piston with with diffrent wrist pin location

I plan to use stock style 9.5:1 454 pistons
and new 427 car moter connecting rods

would there be any advantage powerwise to use the 366 truck block and itake?

I didn't know the 427 had a higher deck than the 396 and 454. Is the difference in deck height because the crank centerline is lower or because the decks are higher?

If the deck is higher, as opposed to the crank being lower, that means the heads are further apart on the motors with the higher decks. Heads further apart, other things being equal, would require a wider intake manifold.

So I've been sharing some vague memories and not facts I had high confidence in. I just looked up some info on the web, but could not find clear details.

I did find bore and stroke for the parts you are using. With a 366 crank in a 454 block, I think you're building a 447 instead of 427.

Somewhere I have a big block book. I'm going to look for it and see if I can sort this out.

Well now I'm a little better educated.

There were both 366T and 427T motors, which have the taller deck, and thicker cylinder walls. The difference is in the deck height, and those motors do require a wider intake manifold.

The rod length is the same, but push rods need to be longer. The guy who wrote the book I'm reading suggests the tall blocks are a good choice for a high performance motor.

Since you are using a 454 block with a 366 crank, either set of rods should work, and with the 454 pistons the short block should be workable. The 366 heads should work, but you'll have trouble with the 366 intake. It won't work on this motor. And you'll want short deck push rods. And the 366 distributor will be the wrong one too.

So I guess to respond to your original question, you're talking about putting heads designed for a 366 on a motor closer to 450 cubic inches. Top end may be limited by the flow those heads will support. The 366 manifold will need to be replaced with a short-deck intake.

Sorry my words are more encouraging.

i read that right you used the 366 heads ? not the best choice very small truck port.pass. car oval port would be the best place to start for heads.366 intake don"t bother wont work use at the the very least edlebrock perfomer. the intake ports on this intake start out about truck head shape.454 and 427 have the same bore size in the beginning 4.250 i do belive. make shure to use proper harmonic balancer and flexplate/flywheel.

I was NOT planing on using the wider 366 itake
and the main reason I wanted to use the 366 heads was to save mony but if it will result in loss of power to hell with that idea
I am just trying to build some buget Horse Power old school style trying to keep away frome buying aftermarket heads because thay can get realy pricy I guess im stuck with a looking for a set of car heads for 454
how did you get 447 instead of

By using the 366's bore instead of its stroke in my calculation... Oops.

You're correct that makes a 427.

the best stock oval port head to use is the casting #781. 781 being the last 3digits of casting numbers. they are open chamber and will work witth your 9.5 comp. if the pistons are open chamber type.should be an easy to find head some what.

IF you're using a tall deck 427 block, then you're very limited on intake choices. You could try to call Summit Racing and see what's available, if anything. (800-230-3030).

The big advantage to the tall deck 427 is that you can improve your rod/stroke ratio by using longer rods. The 427 already has a decent 1.63 rod/stroke ratio and is an excellent revving big block. You can improve that with longer rods to make it rev like a 302 Z28 motor. Drag racers sometimes liked building 427's like that, so they could take advantage of the big hairy solid cams to allow the higher rpms. If you do that, then little 366 heads are probably the last thing you'd want to use. You'd probably want either rectangle port heads or large oval port heads. You'll almost have to use a custom sheetmetal intake in a single plane configuration with a big Dominator on top. I hope you're drag racing and not street driving, with this configuration, because you wouldn't be happy on the street with a 4000-8000 rpm band.

If you want torque, you don't need the tall deck 427! You already have a good motor that revs well and makes good torque in the normal-deck 427. Plus parts are a lot more plentiful. Off-the-shelf pushrods and intakes, for a start. With a good set of bowl-blended oval port heads with large valves, you'll easily get 7000 rpm out of them. I know from experience. And you'll out-power rectangle port heads all day long in total average torque and power. The rect. port heads only make better power above 7000 rpm.

In fact, I'm pretty sure that you can stroke a 427 with a 454 crank and boost the torque even higher, and still comfortably get 6000 rpm out of it with good quality parts.

What exactly is your goal with this engine...let's start there.

Thanks for the help HotRodDad
I was not planing on making a tall deck 427 because,
As you said it would end up being built for the drag strip and I want somthing for the street with an ocasnal run down the strip.
The only reason I had anything to do with the 366 in the first place was the very tough forged steel crank wich would make a 427 out of a 454.
If I had a reguler 427 and wanted to get about 540-580 streetable HP what heads/intake/cam would you sugest that would still leave a littel margine for pulling a trailer or hauling a small load of fire wood

Well, okay. This is going to be a long message.

The 427 I'm running in my 68 Corvette might work for you if you have steep enough gears. But it's more on the race side of things. With a few differences, such as a lower compression ratio (10.5:1) on aluminum heads, so that you can use premium pump gas. It's a solid roller though, but it'll make great midrange torque and will be very powerful up to about 6700 rpm. With steep gearing (at least 3.70), your truck will put the hurt on most hot street cars on the road. It's a hotrod cam, definitely street/strip, and with a dual plane manifold, you would see 504 lb-ft @ 2000 rpm, peaking at 4500 rpm with 571 lb-ft, and it should make about 561 hp at 6000 rpm. The cam is a Crane #138551 with 238/246 degrees @ 0.050" and .595"/.615" lift, int/exh. Idle is a bit lumpy, and it's powerband is advertised to be 3000-6800 (but the intake limits you to 6700).

This motor would require 500 mile valve adjustments, and it is a roller cam. The heads I'd recommend are Edelbrock oval port aluminum BBC heads, and the intake would be an Edelbrock Performer RPM Air Gap. Use full length headers, probably 2 1/8" primary tubes, such as a Hooker Supercomp header. Take your pick on performance mufflers, but your best street/strip compromise would probably be no less than 3" exhaust. Flowmaster is a favorite of mine. Nice sound, great performance.

You can get a "maintenance free" hydraulic roller cam if you don't want the frequent valve adjustments. Power will be comparable, but a few hundred rpm less. For a truck, I'd recommend something like a Crane #138551 hydraulic roller. Powerband is 2000 to 5500 rpm with valve float at 6500. THIS THING MAKES TORQUE!!!!!!!!!!!!!!!!
(214/222 degrees @ 0.050, .553"/.576" lift)

With 10.5:1 compression, you start OFF making 578 lb-ft at 2000 rpm, and it's perfectly flat, peaking out at 583 lb-ft at only 3000 rpm. Your horsepower is 485 at 5000, but with this cam, you will still have a GREAT towing truck and you'll never know it's under 500 hp (albiet just barely). It'll be SO POWERFUL, you'll love this motor. It would be my choice for a hotrod truck with a true towing/street/strip package.

If you want a little more strip talent, but still be a decent towing and street cam, my next recommendation would be a Crane hydraulic roller #139731 which is 226/234 deg @ 0.050" with .587"/.610" lift, int/exh. It starts out making 544 lb-ft which is still excellent, but has more of a rise in torque with rpm. It'll peak out at 579 lb-ft at 3500 and 4000 rpm, and has a slightly higher power peak of 531 hp @ 5500 rpm. This may be more to your liking. And you'll still destroy Mustangs off the line, but continue to destroy them down the road too!

Sorry about the long message, but I profiled 3 different cams for you using Dyno 2000.
Hope you're using a good strong Dana 60 or something like that in the rear! Anything less, and this motor might grenade it.

Hey Dad what is Dyno 2000? It wouldn't be a software tool I could use to decide how to build the 454 for my '52 GMC Extended Cab Dually would it?

Absolutely. You can theoretically build almost any popular engine, and it is not restricted to American engines. There are some European and Japanese engines too. Or, if you know the bore and stroke, you can set up an engine that is not loaded into the program.

Basically, Dyno 2000 is a desktop dyno and is about the most reasonably priced desktop dyno you can find. There are better ones that are a lot more accurate, you do get what you pay for. But for the money, Dyno 2000 is decent.

It has some limitations, they never could get their turbo program to work right, although their supercharger program works fine. (???). Also, some generalizations are made that are not correct, such as the bigger is better carb myth, and no difference between a 60's dual plane and a modern 2004 dual plane.
But for comparing cams and getting a general idea of what your optimum sealevel power/torque curves look like, it's pretty good.

Definitely worth $60 bucks or so.

Thanks Dad! I may need to add that to my Christmas list!

There was a recent article in hot rod about the tall deck engines. You can buy spacers to use the car manifolds on the tall deck engines.

A good friend of mine is running a 1969 Corvette 390-horse 427 in his 69 pickup truck. But he has a milder torque cam in it. It idles extremely well and had enough torque to break a Dana 60 when he dropped the clutch, playing one day.

Anyway, his motor is built, runs great, and is for sale. He wants to part out his truck.
It costs a little over $100 bucks to ship an engine, so do you want his contact info to look into buying his 427???

46: You might look someplace for the 427/425HP motor dang gone thing was awsesome put in 65 Corvettes as a special order. The configuration was big bore w/high compression, and a mile of torque.

Chrysler's answer was the 426 Hemi, Ford tried tried to justify the 428 later. There was (As far as I'm concerned no better engine that the 427/425)

popcorn The Truth is Out There (Yes I drove one a rocket tied to you butt)

HotRodDad,
what kinda price range do you think he will want my buget is realy strict intell spring
because thats wen I plan to realy dig in to my truck project
you can e-mail me at [email protected]

Tell you what, send me an e-mail for him and I'll forward it to him. Best way is to get you in touch directly with him.

His name is Tim.
Thanx.

OK drop you a line after the holidays gonna be offline for a cuple weeks