nastee383

I'm considering putting a big block (502) in my Vette when the time comes. Are there any drawbacks to swapping to a big block? Such as space limitations, header choices, accessories, etc.? I figure I can get a bad big block crate for just about the same or a little more than a big (427) small block crate.

norvalwilhelm

When I bought my 75 13 or 14 years ago I never drove it a single foot. I pulled the small block, sold it and dropped in a high compression LS6 454. I used the original 400 transmission, distributor, rad and power steering pump and alternator. My header are 2 inch primary tubes and they fit fine. Header removal and installation is about 1 hour tops, total. Plug changing is a breeze. I did not use a short water pump at first and used normal mounting brackets for the alternator power steering pump. I did run the stock rad for a few years along with twin electric fans without to much problem.
I even run a high rise intake with 850 double pumper holley carb and dropped base air cleaner with 2 inch high element under the stock 75 hood. I did need to clean the under side of the hood and it rubbed slightly but I drove this combination for years.
I am a big block fan, now I am a blowen fan. I would rather make tons of down low torque then rev the sn?t out of a small block. RPM kills parts not torque made down low.
Go for the 502. I promise you won't be sorry.

75 BBC Stingray

There have been some nice threads on the SBC vs BBC our cars. Try a search. Among the topics discussed:

Weight increase while going to BBC
Handling degradation w/ extra weight of BBC
Replacing radiator w/ aluminum to handle extra HP
Upgrading to electric fans
Hood clearance
locating accessories brackets for BBC
changing drive train components to handle extra HP (Universal Joints)

I'm just beginning the switch w/ an 11:1 fuel injected 454. Wish you luck.

Flareside

IMO, a big block engine compartment is easier to work on than the small block car. The sides of the heads and spark plugs are laid out in a much more user friendly manor. Changing plugs on my angle plug 406 takes longer than changing plugs on my 427.

I think the cost of a 502 conversion will be about the same as the 427 small block crate, since the only 427ish crate motors that I know of cost significantly more than a ZZ502, etc. If I were buying a 400+ cube crate engine, and had a limited budget, I would go with the big block for sure.

There are plenty of header choices for either engine.

BB wowbagger

Well,the only real drawback with a Rat is that the reartires seem to wear down really quick :D :D :cheers:

Ganey

Sus. upgrade unless you have FE-7. Wt. can be reduced w/ al. intake, heads, rad., water pump, etc. You need another hot rod to put the 383 in. Prefer BB.

:cool:

MassVette

Many "pro's", not many "con's".............
Get the 502- you'll LOVE the G-Forces! The one in my '79 pulls like a scalded mule all the way up the end of the 140 speedo and beyond.
:lol: :chevy :chevy :lol:
'Once you've gone Big Block- you'll never go back'!

GDaina

:iagree: :lol: :lol: :lol:

nastee383

GANEY, the 383 and 700R4 is going into my 1994 GMC S15 Jimmy. Already has a 12 bolt welded tubes, bolt-in axles, Auburn Posi, etc. :yesnod:

nastee383

Thanks for the insight. I haven't made up my mind totally but these comments have eased some of the apprehension I had about a big block swap. I like that 630 hp 502 from Sallee but it'll probably be $13K by the time I get ready to buy a motor. It's $11K now. Maybe I'll buy a GMPP shortblock and build the rest myself. I'm so confused! :confused: :confused:

GDaina

http://forums.corvetteforum.com/zerothread?id=458954

Fastguy

I swapped in a 454 and had to change a few things but its all bolt in, no fabication needed. I opted to go with original style Vette parts so I used the short water pump, 74 BB brackets and a 74 PS pump. My cooling sytem is a BB radiator with dual Flex a Lite fans on a T-stat switch. The exhaust is Hooker SC's and 2 1/2 duals. I bought bigger front shocks and springs for it too. If you do an archive search, I posted all the parts I used.

dually4wd

See if I can help... Don't put in the big block, unless you want to get in the 7's WITHOUT nitrous. :)

nastee383

I'll definitely be asking you some questions when the time comes. I'll be spending the next year or so trying to get that Jimmy right. And I'll be looking for 6's (high) without N2O...If that's possible with a C3. :steering: