Topic: someone swapped the 403 6.6 what do I do?!

[silver79]

I bought a 1979 t-top T/A with a rebuilt olds rocket 350. Should I leave the 350 in and build around it or look for a 403... The car is not going to be factory color but I still would like to be close to original. My question is how does my 350 line up to the 403 in looks and performance?

[HughJass]

I bet if you check with some of the Olds performance suppliers either can be made  to make plenty of power reliably.
Since you already have the 350 and your not doing factory resto. work with what you have, put the money you are going to have to spend on a 403 block into the 350.

JMNSHO

[Tin Indians Rule]

What year 350? What heads are on it and have any mods alreay been done to the 350??

[silver79]

I am not sure of the year on the 350 but I know it has like less than 100 miles on it as a matter of fact, the tranny needs to be rebuilt and the car isnt road worthy yet so it probably has 0 miles on it. I think the heads are "C" heads but I dont know much about the 350. I have a 403 in a 79 formula that I bought at the same time for parts. The 403 is painted green though so it is questionable if it runs or not! I could probably rebuild it while I am runnin the 350, that is if the 403 isnt too far gone.

[silver79]

Tin,
I have since my las post found out that my 350 is circa 1969 engine with 375 horsepower. Is that possible and if so is that better than the 403?

[81BlackTA]

That motor is worth a lot of money. They are very hard to findand are way better than the 403, althoughthe 403 can make decent power if you have a bunch of money. Check out this link on the 403 from the Mondello brothers.

http://www.mondellotwister.com/Art403Olds.htm

[81BlackTA]

Oops, I noticed you directed that question at Tin...sorry to butt in but got excited when I read that it was a 69 engine.

[silver79]

where could I find out the specs on the 350?
I had never really heard anything about it until now and I would really like to learn more about it!
does anyone know of any good web sites devoted to the rocket 350?

[Tin Indians Rule]

I am not sure of the year on the 350 but I know it has like less than 100 miles on it as a matter of fact, the tranny needs to be rebuilt and the car isnt road worthy yet so it probably has 0 miles on it. I think the heads are "C" heads but I dont know much about the 350. I have a 403 in a 79 formula that I bought at the same time for parts. The 403 is painted green though so it is questionable if it runs or not! I could probably rebuild it while I am runnin the 350, that is if the 403 isnt too far gone.

"C" heads are some of the best heads thats Olds made. They are 425 Big Block heads and they flow like crazy. Grab the casting numbers off them and the casting number off the block. I'd be curious to know if that is a 69 425 or 455. Hang on to it for sure until you know what you've got. Can you tell the difference between a BB and SB Olds engine?

[Tin Indians Rule]

where could I find out the specs on the 350?
I had never really heard anything about it until now and I would really like to learn more about it!
does anyone know of any good web sites devoted to the rocket 350?

Get those casting numbers and we'll go from there!!

Mondello, Dick Miller Racing and my old work place Cheatwoods Machine Shop all carry the Hi-Po Olds stuff. I've got some "C"  and "F" heads as well as a tunnel ram for BB Olds. Let me know about those casting numbers.

[Tin Indians Rule]

Oops, I noticed you directed that question at Tin...sorry to butt in but got excited when I read that it was a 69 engine.

No worries! We're all here to help. Olds are my first passion. At least when it comes to engines!!! :lol:

[silver79]

well, the car is at my dads house awaiting a 37'x40' workshop to be built. As soon as i can i will let you know the #'s on the heads and block

[silver79]

sad news... i found out that the heads that i have are NOT "C's" i really have no idea as to the identification of them but as soon as i can get over to my dads and pull the engine, i'll get back with you guys.

how does this change my performance knowing that they are not C heads?

should I still stick with the 350?

[Tin Indians Rule]

it's really hard to say until you k now what engine/head combo you have. All Olds heads have either a letter letter/number combo on the left side right at the end of the head. Check there and then get the block casting number if possible.

[DetroitTA]

OK check the heads if they have a "5" on them they those are pretty decent heads (they should be #5's but i dunno) what you can do is pick up a 403, theyre usually pretty cheap then if you want some serious horespower and have a bit of cash around you drill out the head bolt holes to 1/2 inch then you bolt those down, combine those with a decent cam, headers, and an edelbrock 3711 (for shaker clearance) and your golden. If you have even more cash dont hesitate to have the heads and bottom end rebuilt, bored out, milled, whatever.

you can usually get up in the 300'sHP maybe even 400's if you spend more money (like me   )