69 427 need to replace intake gasket
Thread Starter
Instructor
Joined: Nov 2011
Posts: 238
Likes: 30
From: Dallas TX
69 427 need to replace intake gasket
I've never torn into an American engine. My 35 year car hobby has primarily been on Jags.
My 427 is weeping oil in the front seam of the intake manifold and block.
I could use guidance of a punch list for the task.
Do I set the motor at TDC or just mark where the rotor is pointing and put it back i the same territory?
What finish should the bolts have?
Many thanks,
Charles in Dallas
My 427 is weeping oil in the front seam of the intake manifold and block.
I could use guidance of a punch list for the task.
Do I set the motor at TDC or just mark where the rotor is pointing and put it back i the same territory?
What finish should the bolts have?
Many thanks,
Charles in Dallas
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
As you lift the distributor, it's going to turn anyway. I'd just pull it and then remove #1 plug and bump it over until #1 is at TDC, then drop it back in when you're done. As far as the finish on the bolts, you'll need someone that is much more familiar with NCRS than I if you're wanting to go that direction.
Your punch list is going to be pretty short.
Drain coolant
Pull distributor
Remove all hoses and lines- Mark where the vacuum lines connect or take a picture.
Remove coil bracket- (the bracket and coil cover up an intake bolt)
Remove the carb if you desire
Remove the intake bolts.
Pop the intake off,
Clean gasket surfaces. Put 'er back together.
Be aware there are 2 different types of intake gaskets depending on which engine you have- oval port and rectangle port..
Your punch list is going to be pretty short.
Drain coolant
Pull distributor
Remove all hoses and lines- Mark where the vacuum lines connect or take a picture.
Remove coil bracket- (the bracket and coil cover up an intake bolt)
Remove the carb if you desire
Remove the intake bolts.
Pop the intake off,
Clean gasket surfaces. Put 'er back together.
Be aware there are 2 different types of intake gaskets depending on which engine you have- oval port and rectangle port..
Thread Starter
Instructor
Joined: Nov 2011
Posts: 238
Likes: 30
From: Dallas TX
Which ports oval vs. rectangle
Yes, I see there are two different gasket kits.
How do I know which I have without pulling the intake?
This is a 427/390 engine and the casting number on the intake matches the factory intake manifold designation.
How do I know which I have without pulling the intake?
This is a 427/390 engine and the casting number on the intake matches the factory intake manifold designation.
Burning Brakes
Joined: Feb 2012
Posts: 925
Likes: 7
If it is a 390HP engine, you need the oval port intake set.
Is this an NCRS car? Is having the "correct" gaskets important to you or something that works? The intake kits come with cork gaskets for the front and the back of the engine. A lot of people use Permatex Ultra-Seal Gray for the end wall seals. Even if you use the cork, you would want to put some sealant in the corners where the head, block and intake meet.
I use stainless steel bolts on mine, but I think the factory bolts were carbon steel with "TR" on the heads. Not sure though. I would think any of the major Corvette supply houses could get you a set of correct intake bolts.
Is this an NCRS car? Is having the "correct" gaskets important to you or something that works? The intake kits come with cork gaskets for the front and the back of the engine. A lot of people use Permatex Ultra-Seal Gray for the end wall seals. Even if you use the cork, you would want to put some sealant in the corners where the head, block and intake meet.
I use stainless steel bolts on mine, but I think the factory bolts were carbon steel with "TR" on the heads. Not sure though. I would think any of the major Corvette supply houses could get you a set of correct intake bolts.
Instructor
Joined: Feb 2010
Posts: 150
Likes: 8
From: Pelham Alabama
Another thing during your repair.... I would recommend a sealant on your gaskets called "the right stuff". It's amazing stuff and will ensure that you dont have any leaks. You can get it at Advance Autoparts for cheap and it requires a caulking gun for application.
Also, I decided to put stainless steel block off plates in the heat riser passages up into the intake manifold. Some companies supply them with your gaskets like Edelbrock... if you don't care about factory gaskets. This keeps the intake more cool and will prevent vapor lock and boiling the gas out of the float bowl also. The thermostatic choke will work more slowly for your NCRS ops inspection but it sure beats flooding the motor on a hot day.
RC
Also, I decided to put stainless steel block off plates in the heat riser passages up into the intake manifold. Some companies supply them with your gaskets like Edelbrock... if you don't care about factory gaskets. This keeps the intake more cool and will prevent vapor lock and boiling the gas out of the float bowl also. The thermostatic choke will work more slowly for your NCRS ops inspection but it sure beats flooding the motor on a hot day.
RC
