Question: what if you needed a motor

[midyearroadster427]

So...I'm thinking about the future a bit here. If you had your choice...would you buy a gm crate motor...454 or 502 and why? Now for reference...you would be traveling with it..say an avg of 8500 miles a season. NO Garage Queen. I am also thinking about a rebuild of the 427..but with all the miles on it..I am sure I will hear...we need to bore it out a bit..which I do not want to do...soooooooooooooo who thinks what..which is better and why... thanks for your opinions....

 

[Txbobcat]

Bore it and keep it original

 

[crowvet]

Bore it and keep it original

I Agree, if they deck the block make sure they don't grind off your block number.

 

[orlandjoe]

Watch for the crate motor clutch boss. The new ones don't drill out the boss for the mechanical linkage.

 

[Bwmurph]

"BAG AND TAG" your original motor and go with the crate.

That's my $ 0.02.

 

[Tom Bryant]

Rebuilding the original 427 is what I'd do but that depends on what your intended use is. I don't see what the problem is with a .030 over bore. It makes the cylinders round and true again and with the proper new parts should be worth another 100,000 miles or more.

As for decking, I believe that process is way oversold by machine shops. If you are blueprinting a racing engine that's one thing but if it's a street engine, most times it isn't necessary. With the deck surface clean lay a straight edge across the deck in several places. Shine a light on the back side and look for any light under the straight edge. If there is no light at any contact area then it's flat. Same can be done with the heads. What more could be accomplished by decking on a street engine?

Now if you intend to do any hard running or racing then you may be concerned about lunching your numbers matching block. In that case I'd bag and tag as was said above and install a crate motor. You can't beat a GM crate motor with warranty but you will have to deal with the drill and tap for the clutch cross shaft on some blocks.

Tom

 

[NORTY]

"BAG AND TAG" your original motor and go with the crate.

That's my $ 0.02.

Yup, why risk a #'s matching block? I'd use a crate also and drive it. When it's time to sell, you can reinstall the #'s matching engine...

 

[Tom Bryant]

This one would be nice.

ZZ427

 

[BADBIRDCAGE]

Rebuilding the original 427 is what I'd do but that depends on what your intended use is. I don't see what the problem is with a .030 over bore. It makes the cylinders round and true again and with the proper new parts should be worth another 100,000 miles or more.

As for decking, I believe that process is way oversold by machine shops. If you are blueprinting a racing engine that's one thing but if it's a street engine, most times it isn't necessary. With the deck surface clean lay a straight edge across the deck in several places. Shine a light on the back side and look for any light under the straight edge. If there is no light at any contact area then it's flat. Same can be done with the heads. What more could be accomplished by decking on a street engine?

Now if you intend to do any hard running or racing then you may be concerned about lunching your numbers matching block. In that case I'd bag and tag as was said above and install a crate motor. You can't beat a GM crate motor with warranty but you will have to deal with the drill and tap for the clutch cross shaft on some blocks.

Tom

I gotta agree with rebuilding your original motor. Even if you have a deck surface that is out .003 - .005 as long as you run a good composite gasket you won't have any sealing problems.

I don't know why you are against an overbore on the original block. The only way to properly rebuild it is to get fresh, true surfaces and that will require an overbore whether you do it or the next owner does it.

I would also recommend a retro roller camshaft setup from someone like Comp Cams. You can eliminate the worry of losing a lobe to insufficient lubrication as many have seemed to suffer.

From your description of usage I get the feeling you will be driving the car as a cruiser rather than a racer. Nothing wrong with that at all. A properly rebuilt motor will last at least as long as the factory motor did and possibly longer.

I just can't justify pulling an engine, bagging it up and having it take up space on the garage floor for years in order to possibly satisfy some date d!ck who might buy the car from you later in life.

Rich

 

[midyearroadster427]

perhaps I should have mentioned the block was not orig.. as for boring then we get into pistons and such...which now will bring the costs up to probably the cost of a new crate job. so ...I think a question that I should have asked first is ..which is better the 454 or the 502...what are the pluses and minuses of each..thanks guys