ClassicOldsmobile.com - View Single Post - changing intake manifold and carb on 65 olds dynamic 88 425 cid

Oldsproject · 07-05-2007, 04:16 PM

WOW...... I logged on, found a great question, some advice then down hill from there. Well I only have one thing to say then I'll give my advice on the question from 65topless.

The three senior guys above (Joe, Oldsguy, Super 88) have a tremendous knowledge of Oldsmobiles and have personnally helped me in indescribable fashion (also my Medford friend). I've read 40-50% of the posts on this site in all catagories and the knowledge base here is close to unparalled. I know Ryhelio was only helping but certainly misinterpreted Joes e-mail and that in a nut shell is the problem. E-mail is too easy to read into and in my humble opinion, a major problem in business AND pleasure.

As for 65topless, here's what I did with my 425 from a 67 dynamic (Not done yet)........ I went with the Olds Performer by Edlebrock matched up with an Edelbrock 750 CFM carb. Keep in mind though, I beefed up the bottom end with moly straps on the main caps, new high comp pistons, rings, better cam, timing chain, beefed up the valve train, etc.... When I started I was after a solid to top end street car..... what I have is a tire eating monster (which is good)! I'm just now getting the car dialed in and to the point where I can take it for test drives so still have some work to do but yesterday, I stopped and floored it for the first time and had to let off the gas because the tires were still smoking (about 50-60 yards)..... that's good and bad. Good because I have ample power to the wheels, bad because it's not controlled yet (probably need posi in the rear) and any fool in a Hyundai (OK overstated a bit) will eat my lunch as I sit there and smoke up the place. My personal opinion is that the simple change to the bigger intake and a bigger carb (600 - 750) will significantly improve what you already have. If there was one other thing I'd do without a lot of money it's headers and higher flow exhaust. I used hooker headers combined with the 2 1/2" header back kit from Jegs. If there's one thing I learned, Olds engines need to breath.... the more you can help the intake AND exhaust..... the more you'll get.

Keep in mind, my 425 was my first project so listen to the experts and browse the site. There is good information here.

By the way, couple tricks I learned by reading Mondellos books..... get some Gaskanich glue, apply glue to the intake and top of the gasket, let it tack up then glue it to the intake, then glue the head and the bottom of the gasket, use high temp RTV around all of the water jackets and DO NOT use the rubber gaskets on the ends. Build them up with some good RTV. The seal you get is tremendous if you take your time and do it this way. Otherwise, better chance you'll have leaks and it's a bitch getting the gaskets on right.

In any event, goodluck and welcome! If you have any questions I can give you a blow by blow on what I did and some helpful do's and dont's (learned the hard way). That 425 is arguably as good as most 455"s (my opinion only) as there really isn't a tremendous amount of differance and they have forged steel cranks which seem to hold up better to higher RPM applications but a little less tourque then the 455.

Any event, my 2 cents from the peanut gallery.

07-05-2007, 04:16 PM	#17 (permalink)
Oldsproject 65 post sport coupe w/425 Join Date: Mar 2007 Location: Oregon City, Oregon Posts: 76	WOW...... I logged on, found a great question, some advice then down hill from there. Well I only have one thing to say then I'll give my advice on the question from 65topless. The three senior guys above (Joe, Oldsguy, Super 88) have a tremendous knowledge of Oldsmobiles and have personnally helped me in indescribable fashion (also my Medford friend). I've read 40-50% of the posts on this site in all catagories and the knowledge base here is close to unparalled. I know Ryhelio was only helping but certainly misinterpreted Joes e-mail and that in a nut shell is the problem. E-mail is too easy to read into and in my humble opinion, a major problem in business AND pleasure. As for 65topless, here's what I did with my 425 from a 67 dynamic (Not done yet)........ I went with the Olds Performer by Edlebrock matched up with an Edelbrock 750 CFM carb. Keep in mind though, I beefed up the bottom end with moly straps on the main caps, new high comp pistons, rings, better cam, timing chain, beefed up the valve train, etc.... When I started I was after a solid to top end street car..... what I have is a tire eating monster (which is good)! I'm just now getting the car dialed in and to the point where I can take it for test drives so still have some work to do but yesterday, I stopped and floored it for the first time and had to let off the gas because the tires were still smoking (about 50-60 yards)..... that's good and bad. Good because I have ample power to the wheels, bad because it's not controlled yet (probably need posi in the rear) and any fool in a Hyundai (OK overstated a bit) will eat my lunch as I sit there and smoke up the place. My personal opinion is that the simple change to the bigger intake and a bigger carb (600 - 750) will significantly improve what you already have. If there was one other thing I'd do without a lot of money it's headers and higher flow exhaust. I used hooker headers combined with the 2 1/2" header back kit from Jegs. If there's one thing I learned, Olds engines need to breath.... the more you can help the intake AND exhaust..... the more you'll get. Keep in mind, my 425 was my first project so listen to the experts and browse the site. There is good information here. By the way, couple tricks I learned by reading Mondellos books..... get some Gaskanich glue, apply glue to the intake and top of the gasket, let it tack up then glue it to the intake, then glue the head and the bottom of the gasket, use high temp RTV around all of the water jackets and DO NOT use the rubber gaskets on the ends. Build them up with some good RTV. The seal you get is tremendous if you take your time and do it this way. Otherwise, better chance you'll have leaks and it's a bitch getting the gaskets on right. In any event, goodluck and welcome! If you have any questions I can give you a blow by blow on what I did and some helpful do's and dont's (learned the hard way). That 425 is arguably as good as most 455"s (my opinion only) as there really isn't a tremendous amount of differance and they have forged steel cranks which seem to hold up better to higher RPM applications but a little less tourque then the 455. Any event, my 2 cents from the peanut gallery.