I have an opportunity to purchase a GM Winters Aluminum Intake for the 454 that is supposed to fit under the stock hoods from 68-74. I have already bought another set of LS4 heads that are "done" and also from a 74 Vette. This is what has been done to the heads....
Partial description from the seller:

"Larger oval shape runners with high flow characteristics, induction hardened seats for unleaded gas, semi-closed chamber for better combustion, and exhaust valve rotators for better sealing and longer valve life. They have a fresh valve job with back cuts on all valves, which flow a lot better as the valves first start to open up, with the best increase around .300 lift. This means much better, flatter torque curve thus more tire burning response off throttle(also a little better gas mileage). On the street, torque and throttle response are what you're looking for, and that's what these offer! All valve have had "Moly Pro-Tek" dry film lubricant baked on, which is burnished into the metal and provides more horsepower, longer valve/guide life and reduces friction. The springs and retainers also have a baked on finish. Both the intake and exhaust runners have been lightly pocket ported, contoured, flashing removed, and intake gasket matched. They have a rough finish, which helps keep the gas from reforming droplets for more horsepower. Valves lapped in and new valve seals of course. stock valves, & valve springs."


And since the engine is out, I have taken the advice and opportunity to do the engine as I may never get this chance again, once I get the car back together.
My question is; do you feel the aluminum intake would be a good investment and addition to the motor? From what another member had mentioned is that the stock intake is restrictive on these motors.
I will probably also end up changing the cam and lifters, but will need to research that more to see what is the best way to go.

Thanks for any info provided.............................Tom

 

That intake is going to be for rectangular port heads..not the ovals that you have. It will physically bolt on and run OK....but there will be a HUGE port mismatch unless you really open up the heads at the inlet.

It would be interesting to see what they actually did to those heads. With stock springs, valve rotators and stock valves with a backcut on them...they aren't really anything past a stock rebuild with a little cleanup. Maybe post some pics and get the last 3 digits from the casting numbers. Semi-closed doesn't sound like normal '74 454 stuff.

What are your plans for the motor? Those may still be great heads....but it would be good to see pics etc.


JIM

 

what is the difference between this intake and the LS6 intake. that one is reported to run beautifully on oval port heads until way high rpms.

 

Numbers from the intake would help too.

 

I'm assuming that is what he is getting...the flat pancake intake with rectangular ports and a Holley.

It WILL run.....but again...it's not perfect by any stretch of the imagination. The trick is that even though it's mismatched the runners are much larger than the oval ones and it allows a little better breathing. Super Stock guys have run very fast with that intake over the years. But it's only advantage is it goes under a low hood....definitely not a big power maker.

JIM

 

thats the intake i have on my 454 crate motor. didnt get to drive it much before i left for korea but from what i could tell its good enough for a street driver.
my dad took it out the other day to "freshen up the gas" as he put it and wrote me saying that it pulls real fast to 100. funny stuff.

 

I've got that flat intake on Ol' Red. No complaints about it making power. That LS-7 likes it pretty well. Now that I have enough hood, I can put the open plenum intake back on. Or maybe the 2x4's.

 

GM Winters 3963569 intake
the heads are 781 same as what I have on the car now....
here is the link for the heads, there are pics posted ...
http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWAX%3AIT

thanks for the replies, appreciate the info...always learning, sometimes to late......

 

if this manifold requires me to get a Holley, I will pass, as I am leeping the Q-Jet......guess I am not thinking clearly these days....

 

It is for a Holley.
There are only 3 factory low rise Qjet aluminum manifolds for the Corvette.
They are 849, 801 and 793.
Hope this helps.
Terry

 

sure does, thanks for the #'s....apppreciated.....Tom