69vette66

Hi All. I would like to swap a big block in my my '69 350/350 auto. What all do i need to change, motor mounts, brackets, pulleys, flywheel. What other problem will I encounter by doing this. Will my small block hood clear? I will be using a 850 holley and sidemount headers.Any info would be grateful, this would help me decide to go big block or 415 small block.

Thanks for your time Larry :chevy

Tominator

I'm not much help with your question, but what motors have you decided on crate or rebuild. I noticed that one of your choices was a sb 415 that sounds nice too.

Gordonm

I like big cube small blocks myself. A 415 small block is a good idea. Less weight better handling. The small block hood will not clear. If you use a high rise intake you will definitly have problems with clearance. My .02 cents

Larry B.

A big block will bolt right in. BUT... You will need a BB hood and if you want to us any kind of aftermarket intake,carb, etc., you will need the L-88 hood. You will also need all of the accessory bracketing. You will need a flywheel and harmonic balancer if you are using a 454 or bigger as those are externally balanced engines. You will need headers OR Corvette big block exhaust manifolds. (expensive) You will also may need to replace the radiator depnding on what you have in there now. :cheers:


[Modified by silvervetteman, 11:16 AM 2/9/2002]

ykp53

I have a 1977 corvette w/ a 454, a standard gm intake , a edelbrock 1910 carb and a 3" k&n filter all under a standard hood. No big block, no L-88. I have heard a lot of guys say that this combo wont fit but mine does with about a 1/2" to spare? Any one care to figure this one out? :confused:


[Modified by ykp53, 12:30 PM 2/9/2002]

454Big

I also have a 454 in my 77.
I use a Torker II intake and currently a Holley 4150.
My aircleaner is a Edelbrock Pro Flo.

It all fits under the stock 77 SB hood.
I performed the swap from SB to BB myself, had to change the bracketry and the belt routing. Manufactured some pulleys and brackets of my own by using a lathe and aluminium.
Problem is the radiator - go as big as possible.
If using headers, be sure they clear the steering box and the idler arm.
Mine had contact...... for some time, then the fixed it themself :lol:

BB driving is a great experiece - boatloads of torque.....

All SB guy forgive me, but you just don´t know...... :D

Larry B.

Ok. ... you guys do not have 68-72 small block hoods, they are different. That's why big blocks fit... There are no 73-up big block hoods except aftermarket.. :boxing

ScubaJKD

Go big cube small block and bolt it right in, save the wieght, get all the performance you want, save the bucks, and reduce PIA factor.

:cheers:

Bob Turner

I am doing the same swap (Mouse motor to 454). The only pain I can see is getting the right pulleys and brackets (P/S, alt, smog pump). :crazy:

I am planning to go with a VintageAir set up, so they include the brackets.

I am not that far yet, so I don't have much else to report!!

That 415 mouse motor isn't a bad deal if you go with it... I just want to see that huge BB under my hood.

Bob

bence13_33

Bob:
Smog pump....we don't need no stinking smog pump! :D j/k

69vette66:
I'm currently switching over to a big block right now too. By far the biggest PITA is trying to track down the correct brackets. Purchasing new big block brackets is quite expensive too. The big block will bolt right in for you, but your hood is going to have to change (big block hood or an L88 hood).

After my first ride in a big block car I knew that I just had to have one! The torque of a big block is just out of this world. Don't get me wrong, small blocks are nice, but my God THE TORQUE! Which ever way you decide to go (big block/small block) I'd definetly go for cubic inches.


[Modified by bence13_33, 10:21 PM 2/9/2002]

69vette66

Man you guys are making it hard on me, Big Block or a 415 small block. I like the idea of a 415, but i like the big block. I am not going with a crate motor, I will build from scratch. I have the 400 sb and i found a older 454 complete, so it just deciding which i want to do, before i paint my car. just about ready for primer then i will build motor. Yes they do make sidemount headers for big block vette with side pipes, I already checked it from my sources.

Thanks for all your input Larry :chevy

Terrys69coupe

Personal experience is the big block is the way to go.Sold my tweaked 69 small block coupe to my dad and bought a 68 convertible with a 454 .We've driven them back to back and the set you back in your seat torque .Theirs no comparison .Big blocks make their power down low with out having to wring them out,for the same #s.I feel the flames at my neck already .I was a firm believer of small blocks even built a 391 stroker. But one big block ride is all it took.Then the cam comparison and rpm differences and i was hooked. :chevy :chevy

Tom73

One thing not mentoned so far is stronger front springs to handle the added weight. Then you may need to make so changes in the rear to ballance the suspension.

tom...

Larry B.

In all fairness here, I have had both. I do prefer big blocks but.. They do have a few drawbacks. They do not tolerate as high of compression ratio without pinging. 93 octane is a must. They tend to run hotter in Corvettes. They are very senistve to timing/temperature changes. They will never get the same gas milage as the small blocks. With your 69, even the stock 454 intake an Q jet (unless it came from a 70-72 corvette) may not fit under a standard big block hood. Those manifolds are "low rise" designed for Corvettes. I don't believe there are any aftermarket manifolds that will work. Maybe someone knows? :eek:

Ganey

The med. rise 73-79 hood has more clearance than most.

:cool:

shawn_cake

I agree with 454BIG

GO BIG or go home..

:cheers:

gdh

Tough choice, I have a 72 so a bb means a new hood for me as well. BTW what are you going to do with the "losing" entry? Can we start a line now, oh ya can I be first in line, :yesnod:
Good luck but I get the sence that the cu. and torque are winning. :cheers:

noskillz

a 350/350 motor seems like a pretty decent motor. Good performance, good mileage, nice handling, cheaper parts. Plus they were somewhat rare in '69.

MassVette

Big block is the way to go; MUCH more torque........Pulleys and brackets are expensive from Corvette suppliers, but half the price for BB Camaros (SAME brackets and pulleys!) Here's a url:

http://www.classicindustries.com

Hey, you C-2 guys-- check out the teak wheel for the Camaro; look familiar? It's half the price, too!
:yesnod: :chevy :chevy :yesnod: