[Nhurt]

Hello all, I have a friend who has a few BB
Bare blocks that have been sitting in the garage for 15+ years. They will need to goto the machine shop to get freshened up. They offered me a pick of one if interested for free. They have 427's and 454's. I currently have a sbc 327 in my car. I wanted to eventually get a blueprint 383 and drop it in but now these popped up. Realistically whats the ball park damage to get one of these going again all said and done...headers, engine mounts, pulleys, starter, if I build one and which would be better? 427 or 454? Or stick with the crate engine plan so I'm not starting from scratch with everything? I wouldn't go crazy with top shelf parts just a strong street engine. I have a feeling I would be going down a rabbit hole parts and cash wise. I'm looking to be reasonable. Thanks.

 

[ilikeike]

454” plus like 10 0r 20+“ is only like $7k from Blueprint with a fat warranty, and awesome Torque !!!
if you go to a local very reputable engine builder, the $7k is a sweet deal for a built and warrantied long block.
I would not waste my time and money, unless I was building a no nonsense top effort build, which is easily double or triple that from a good local race shop.
Heck
My SBC is sic, but it’s double that $7k.

 

[ss27]

454” plus like 10 0r 20+“ is only like $7k from Blueprint with a fat warranty, and awesome Torque !!!
if you go to a local very reputable engine builder, the $7k is a sweet deal for a built and warrantied long block.
I would not waste my time and money, unless I was building a no nonsense top effort build, which is easily double or triple that from a good local race shop.
Heck
My SBC is sic, but it’s double that $7k.

The first thing i would do rather than pick eeny meeny miney moe is get the numbers off both engines to see what they came out of and the H / P ratings of both then go from there . Next thing to keep in mind is there is a huge difference in price between a refresh and a rebuild. A 390 horse 427 was a bullet proof work horse years ago couple that with a better cam hraders intake carb recurved dizzy you have a nice street engine. On the other hand there's the 454 with 781 heads this you also need to check if its a tall block. If it is a tall block i would use the 427 if not just mark a quarter and toss it. Either way you can build a nice engine the 427 is an internal balance the 454 is external balance like the 400 sbc.Bothe will be a huge improvement in get up and go over your 327 especially if its a low horse power engine . the other thing is depending on the year of your car if its 1970 and under the 427 was onthe RPO list after 70 and later it was the 454. I think you will be happy either way when done. Prices for machine work have really escalated i wish i was a young man for the amount of work i did at these prices i would be mingleing with the likes of Gates BEzos all the big money men . i would build a bbc 427 with all new parts complete for 2,300 to 2,700 depending on parts and earn a handsom living . With todays prices back then i would be walking around like Bonney prince Charley or Diamond Jim Brady. Alex

 

[Harris Roc Malouda]

Hello all, I have a friend who has a few BB
Bare blocks that have been sitting in the garage for 15+ years. They will need to goto the machine shop to get freshened up. They offered me a pick of one if interested for free. They have 427's and 454's. I currently have a sbc 327 in my car. I wanted to eventually get a blueprint 383 and drop it in but now these popped up. Realistically whats the ball park damage to get one of these going again all said and done...headers, engine mounts, pulleys, starter, if I build one and which would be better? 427 or 454? Or stick with the crate engine plan so I'm not starting from scratch with everything? I wouldn't go crazy with top shelf parts just a strong street engine. I have a feeling I would be going down a rabbit hole parts and cash wise. I'm looking to be reasonable. Thanks.

me personally would go for a blueprint SBC 400 or 396 with both around 500 lbft/hp and sell the rest..
least amount of problems and i would guess best bang/buck ratio after you sold what you dont need..

PS: 396/400 both have fully forged rot. assembly. worth the few hundred bucks over the 383 in my eyes, plus you get extra power..

 

[X-77 keith]

me personally would go for a blueprint SBC 400 or 396 with both around 500 lbft/hp and sell the rest..
least amount of problems and i would guess best bang/buck ratio after you sold what you dont need..

As much as I like the 427 , I have to agree with this statement.☝👍

 

[Michael Eusebi]

This what I am in the process of doing to do the switch 327 to 454. Got the 454 cheaper than the 327. Add 750 carb, 11-423-8 cam, air gap has 820 heads hopefully little more power but still very streetable.

Car - power steering you will need all brackets.
power brakes - your choice not needed
frame mounts
motor mounts
new rad
new rad shroud
pullies and brackets
front springs
bigger front stabilizer - might be a nice to have
Rear stabilizer bar - I have heard this might be a waste of money
mutli-leaf rear springs mono were shot if you have good ones no need to worry
Rear end already had a 12 bolt no issue unless you have 10 bolt you make break it
Headers
if 4 speed big block z bar
transmission cross member
Heater coil and box
new hood to clear intake

I have always been a small block guy. Just want a big block for once. If the final intention is go 383 I would not go near the big block my opinion only.

 

[buenymayor]

I'm a BB guy, but if all you are getting is a block, I would pass unless you have a BB around you can rob the 10,000 little parts you will need to get it going. If you are really wanting a 383 BP engine, just go that route. It'll be cheaper in the long run, and will probably meet your goals power wise. There is a whole list of parts that need changed to properly put a BB in an original L6 or SB first gen. Those will just add $$ to the build.

 

[copo9560]

How much power do you want and how much are you willing to pay to complete the installation. A Vortec Pro 467 would cost more than a Blueprint 383 or 396 but provide more hp and torque in a very OE look.

If the available BB’s require a rebuild why not go to a 489/496? Might not be much of a cost difference.

 

[Bob Tiley]

427 and 454 are the same block so just pick whichever one has the best measurements and passes a Magneflux test. You will probably need to have a machine shop measure the bores and mains to make sure they check out OK and do the Mageflux. If you don't have a rotating assembly and heads along with those blocks you are going to spend and easy $5k to $8k on parts and machining. If you can get a good crankshaft and heads along with them you could save a couple grand. Then you will need a few thousand for accessories.

 

[jadams]

Back in 1980, I transplanted a 427/385 out of a 68 Impala into a 69 Chevelle SS 396/325 hp car. I was racing a 442/455 olds Cutlass locally and getting stomped every time. The 396 was tired, and the 427 was fresh. By the way , I won. Fast forward a year to a 1970 SS 454 Monte Carlo. Not a Chevelle but close. Hands down the 427 would eat its lunch. That Monte was ok, and I never had the pleasure of driving a 454 Chevelle for apples to apples comparison. I vote 427. All I have is real world experience to offer.

 

[fairfax1000]

Remember that no GM car would ever have more advertised hp than a Corvette.
427 Tri Power? Only in a Vette.
ZL1-427
COPO-427
I see a pattern……

 

[copo9560]

Remember that no GM car would ever have more advertised hp than a Corvette.
427 Tri Power? Only in a Vette.
ZL1-427
COPO-427
I see a pattern……

LS6 at 450hp was only available in 1970 Chevelle SS, highest 1970 Corvette was 390 hp.

 

[ramblin67rs]

427 and 454 are the same block so just pick whichever one has the best measurements and passes a Magneflux test. You will probably need to have a machine shop measure the bores and mains to make sure they check out OK and do the Mageflux. If you don't have a rotating assembly and heads along with those blocks you are going to spend and easy $5k to $8k on parts and machining. If you can get a good crankshaft and heads along with them you could save a couple grand. Then you will need a few thousand for accessories.

Agree on this. 427also rings better to a Camaro since the 454 was not an option on a 1sr gen. You’ll get enough HP from 427

 

[fairfax1000]

LS6 at 450hp was only available in 1970 Chevelle SS, highest 1970 Corvette was 390 hp.

Correct….and I’m sure some people lost their jobs over that “look at me”. But I do believe the L88 was 435

 

[Larry Madsen]

Just my opinion:

If you are looking for plenty of well mannered power in a street engine there is no better way than adding cubic inches. Torque is the name of the game.

If you go big block, go 454 (or more). If you like the “427 moniker” tell everyone it’s a 427.

Only those truly ear trained to the exhaust note of a “big” big block will ever know the difference.

Been there and done it. 😜

 

[srode]

Remember that no GM car would ever have more advertised hp than a Corvette.
427 Tri Power? Only in a Vette.
ZL1-427
COPO-427
I see a pattern……

Vintage yes, otherwise not correct really

 

[CityguyUSA]

The first thing i would do rather than pick eeny meeny miney moe is get the numbers off both engines to see what they came out of and the H / P ratings of both then go from there . Next thing to keep in mind is there is a huge difference in price between a refresh and a rebuild. A 390 horse 427 was a bullet proof work horse years ago couple that with a better cam hraders intake carb recurved dizzy you have a nice street engine. On the other hand there's the 454 with 781 heads this you also need to check if its a tall block. If it is a tall block i would use the 427 if not just mark a quarter and toss it. Either way you can build a nice engine the 427 is an internal balance the 454 is external balance like the 400 sbc.Bothe will be a huge improvement in get up and go over your 327 especially if its a low horse power engine . the other thing is depending on the year of your car if its 1970 and under the 427 was onthe RPO list after 70 and later it was the 454. I think you will be happy either way when done. Prices for machine work have really escalated i wish i was a young man for the amount of work i did at these prices i would be mingleing with the likes of Gates BEzos all the big money men . i would build a bbc 427 with all new parts complete for 2,300 to 2,700 depending on parts and earn a handsom living . With todays prices back then i would be walking around like Bonney prince Charley or Diamond Jim Brady. Alex

Yeah , but the parts have exploded in price as well. A 650cfm carb is $700 or $800 not $200 or $300. Bolts are ridiculous.

 

[BillDini]

You need to take weight into consideration between the SBC and BBC. Handing will be drastically affected in a Camaro. I owned a 1970 Vette with a 454/390 and my 74 Z28 with a 1970 LT1 Chevy crate engine back in the day with headers and nice exhaust would smoke it. My 68 Chevelle L79 convertible with the 327/325 (now a 331) is a great street car and one of my all time favorite driver cars. It comes down to what you want out of your car and the type of driving you do.