New Engine need input

[beeterolds]

my 83 cutlass went 13.30s at 107mph with this combo...

Stock bottom end.. STOCK no mods.. dont worry about the mains.. as long as your not running NOS, 12.0 compression and spinning it beyond 5500 for long periods of time...

Stock bottom end... and i mean stock.. just re-ringed.. even down to a stock SAgear timing chaing and Melling M22 oil pump and pickup
1972 350 heads, stock valves.. Egr bumps ground down...
Comp Xe262 cam .475 .480 lift 218-224 dur. @ .050
Edelbrock Performer Intake.. (i tried the RPM it made a noticeable difference in top end power.. but never ran it at the track) the rpm will also NOT clear a stock hood..
Home rebuilt 750 Q-jet
Stock manifolds and true duals no cats...

3.73 rear gears, with a Tci streetfighter Th350.. this is a 12 second combo if you run headers and sticky tires, but if you have the stock 7.5 rear sticky tires arent a good idea...

with the 350 heads and a fel-pro gasket your compression will be somewhere around 9-9.5-1 if the heads are milled.. but if you have some extra coin to play with, a set of flattop pistons and ANY big block olds head would probably be a good choice too..

 

[HighHPCouch]

Ok well i have more access to BBO heads than i do to the 72 small blocks that everyone likes the closest thing that i can come into contact with as far as sbo is a #5 set. But i have been told that for my application when it comes to BBO is the C casting head which i have access to two sets of these heads. My question is what do i have to do to get these BBO heads to work on my 403 SBO??? I really want to keep all of the 307 accessories including AC this is the Supreme Brougham model and i want to keep it that way!

 

[dan2286]

Ok well i have more access to BBO heads than i do to the 72 small blocks that everyone likes the closest thing that i can come into contact with as far as sbo is a #5 set. But i have been told that for my application when it comes to BBO is the C casting head which i have access to two sets of these heads. My question is what do i have to do to get these BBO heads to work on my 403 SBO??? I really want to keep all of the 307 accessories including AC this is the Supreme Brougham model and i want to keep it that way!

You don't have to go with 72 heads, the #5 heads will be just as good or better than the 72 heads. #5 heads are supposed to be the best flowing small block heads and will be a nice upgrade for a 403. If you go with BBO heads you will want to change to high compression pistons to get the full benefit of them. Also, to be able to use big block heads I believe the stock intake will not work. I forget what intake you need to get, but I believe it is the performer Rpm.

 

[HighHPCouch]

Ok now that i think that i have a pretty good grasp on what i want to do with the motor i need some input on the trans. I am running the 403 with a Grand National 8.5 rearend with 3.73's and a posi. Now i have three options for a trans....350 turbo, the factory 200r4 from the 307, or I have easy access to a 700r4 that needs rebuilt too. So here is the deal I want something that will harness the power and still be nice on gas for crusin, highway, and some daily driving cause i am not trailerin this thing it is being built to drive.

 

[dan2286]

Ok now that i think that i have a pretty good grasp on what i want to do with the motor i need some input on the trans. I am running the 403 with a Grand National 8.5 rearend with 3.73's and a posi. Now i have three options for a trans....350 turbo, the factory 200r4 from the 307, or I have easy access to a 700r4 that needs rebuilt too. So here is the deal I want something that will harness the power and still be nice on gas for crusin, highway, and some daily driving cause i am not trailerin this thing it is being built to drive.

It depends on what type of money you want to put into it. The 350 should hold up to the power just fine, you will just need to get a different crossmember. The 700-4R may hold up to the power, but it just does not have a great gear ratio for driving on the street. They were made for trucks and that is why it isn't the best choice for a car. The 2004-R will need to be upgraded to handle the power, but it will yield the best fuel economy. You can get one to handle the power for around $2000. Don't know if that is too much for you, but it will be the best one for your application. If you can't afford that, get a 350 trans and get a lower gear ratio, like 3.08s. It will help with mileage and still be strong.