"quick" opinion on 427 tall deck
 

Hi guys,

I found someone that has a 427 tall deck long block for sale. PO bought it 6 years ago (crate engine) and has put about 15k miles on it. There was a small engine fire and they pulled the engine out. The seller has the intake with the melted carbs still.

The engine is a long block minus carbs, intake, WP, and distributor.

The engine turns freely (with a big wrench) and still looks new. He is asking $800 but I am going to offer $500. I did some research on the forum and the tall block does not seem to be the best block for the Corvette since it sits taller. I may have problems with hood clearance, headers, extra cost of buying a tall intake or use adapter to fit stock 427 intake but then I have to mill the intake so the distributor will work. My Vette does not have booster brake so that should not be a problem.

Other than that I like to thinker so I think it can turn out into a nice project.

Should I keep looking for a standard deck or should I pick it up tomorrow????

Thanks,

Gio

One of the big problems with a tall deck block in a vette is the extra height makes it wider too. Header clearance gets to be a problem with the steering box. Nothing that can't be fixed, it's just another hurdle. After that, there is hood clearance (always a problem on a Vette) and the rest of things you mentioned. Intake, distributor are all easy fixes.

You should be able to buy a short deck longblock for that money. The heads on that truck engine are small ports, you'd have to replace them right away. If you're wanting to build a 427, the factory forged piece is fine, but you'll be replacing that, too, if you decide to go with max possible cubes.
I would pass, too many problems with 'em.
Unless you're planning 650+hp, find a good 2-bolt block out of a farm truck, that block will be well seasoned and never revved over 4K. The "best" is supposed to be the '72 - '74 "289" casting, supposedly has thicker cylinder walls.

Run away from this, as fast as you can. These blocks were taller to allow the use of a 4 ring piston. Great for trucks. Crap for cars.

A "small" fire....that melted the carb??? :willy: I don't think so. :toetap:

See to believe :rofl:. The engine looks pretty darn good unless the intake with burned carb came from another engine :rolleyes:. I made him an offer and if he does not take it I will walk away. These engines are unobtainium locally.

Tall deck blocks are great for building BIG stroker motors, if you have a car that they'll fit in. Other than that, they make good boat anchors.

The guy used to build HP motor boats but went into the equipment business a few years ago. He agreed that the engine would not be suitable for the vette so I passed on the engine.

Good choice-hood clearance is bad enough with a regular BB. Then you have to have a tall-deck distributor, bracket issues, exhaust issues, need different heads....

I currently have a talldeck in my 75...And believe me it was a hassle to fit.. and i even have the 4 inch cowl hood!!! However i shoehorned it in there because i had a few dollers tied up in it(aluminum after market heads.H-beam rods.special pistons .roller cam etc.) I wouldn,t however call my 496 a BOAT ANCHOR... Take it from me a standard deck pass block is the best choice alot more choices .cheaper to build and ALOT less hassle..

LOL, I ended up buying the engine. I paid less than $500 so I may be selling some parts and then build a super mega huge boat anchor :-). Mine has a 4 or 5 inch cowl hood too but I guess that is the least of my worries.

I may be interested in the heads - pm me with the casting numbers.

Those tall deck blocks make mountains of torque do to the lesser rod angle [longer rods]
With .250 strocker and .310 bore .I use 049 heads or 781s [big oval ports] and port match them to flow with the square port intake [edelbrock TD-454] which is machined
to utilize the standard length distributor.The only problem I had with these motors is valve train geometry[wiping lobes] The simple fix is to install a roller.
you will need wider tires.
Good luck on your project.

Get rid of the 6.135 rods buy a set of 6.535 rods then you can use standard 427 pistons or better yet bore it .060 use a 4.00 crank for a nice 467 cubes with a better rod ratio then a factory 427/454.
426 hemi had a real tall deck 6.80 long rods, slowed the piston speed down made side loading of the cylinder walls better. in those long nascar races at 7600 rpm, while the short rod, BS stud rocker system big block chevies were falling apart blowing up on the track the tall deck (believe its around 10.8 deck hemi) was just easing around the track with durability , not to mention better breathing heads more power.

King Richard Petty 200 nascar wins, no one has even won 100 races
today.

If you can't beat the hemi on the track you get the rules changed,
even to the point of small blocks, big cube engines no longer allowed.
So get that boat anchor engine going. :thumbs:

:iagree:
Build a nice stroker out of it, I've ran several tall deck 496" strokers over the years in boats.

Numbers on the heads are: 10052902 J252 CFD GM3
Engine Part number: 12353945

I am not ready to part of rebuilt it yet. Can you tell me plus and minus of the heads? Is there anything I can do to increase the power by changing cams and porting the heads or it is better to get new heads?

1052902 shows to be 427 truck, open chamber, oval port.
run the heads the way they are don't port them. pistons are
heavy very tall compression height assume they have 4 rings like the old 366/427 tall deck truck engines of old.

You guys are giving waaay too much credit to the rod ratio helping make more power, etc. It's been dyno and track tested mega times and the results are always the same: nada.

Theres advantages and disadvantages to longer rods, it depends on what someone wants to use the engine for.

I took the heads off last weekend and I was astonished to see the condition there in. The valves and cambers and springs looks brand new. Same for the block, you can still see the hone marks. The STD pistons has some carbon build up. I feel kinda guilty to stroke the engine.... it looks like it should go back in a dumptruck and retire as a stroker in 200-300k miles from now (insert smiley face here, lol). How much can I sell the heads for? I would go with aluminum if I decide to stroke.