1990 Brougham 5.0 to 5.7

[Morgan Murphy, #17409]

My wifes 1990 Delegance is a fine car (with just 27,000 miles) but unfortunately, it only has the 5.0 engine (140 bhp).  

Id like to improve the performance of the car up to 5.7 specs (185 bhp in 1992).  Theres a world of difference between my wifes car and our other 5.7s.  That said, I do not want to alter the original appearance of the engine, other than perhaps adding the air cleaner off the 5.7.

Can anyone tell me how complicated and feasible this project might be?  

[Michael Stamps 19507]

Phsyically the 305 and 350 blocks are the same.  My only concern would be engine managment.  You can get way more than 185 bhp and still keep it stock appearing.

Stampie

[Mike #19861]

 Actually the 5.0 litre engine in your car is the Olds 307 which is a woirld of differance from the 5.7 which is a Chevrolet engine.

 Many changes would be necessary to convert it to the 5.7. It would be cheaper and less aggravation to just locate a later Brougham with the 5.7.

 But, being an olds engine, many have been upgraded to an Olds 350,403 or even 455. With the larger engine, performance is exhilerating, but the trans needs to be upraded as well to be alvle to live with the torque generated by the 455.

 Mike

[Michael Stamps 19507]

They still used those Olds engines that late?  My fault on the answer.  If you really want a 455 Olds you can get a lot of power out of em.  350hp would be considered mild.

Stampie

[Rusty Shepherd CLC 6397]

Its easy to get confused on those 5.0 engines. Probably the easiest way to tell if its an Olds engine (other than the Y in the VIN)is the location of the oil filler.  On the Olds block, the filler is a tube at the front of the engine in the middle while on the Chevrolet its a cap on the valve cover.  Also, all the 5.0 Chevrolet engines used in the Broughams had throttle-body fuel injection (TBI) while the Olds engines had 4BBL carburetors (but youd never know if from driving one). I think putting a lower (higher-numerical)rear axle ratio would give the car better performance with the Olds engine. If I remember correctly, the 307 Broughams (and 98s and Electras) came with a 2.56/1 ratio while the RWD HT4100 Cadillacs had something like a 3.41/1 rear end.  I drove both a 307 98 and a HT4100 RWD Sedan de Ville in the mountains of Colorado when they were new and the Cadillac went up the grades with no trouble while the Olds could barely get out of its own way (I turned around halfway up Pikes Peak).

[Mike #19861]

 The HT4100 powered RWD Cadillacs uses a 3.23:1 gear. In 1986, when the Olds 307 became standard, the gearing was 2.74:1. Thats the gear I have in my 86 Fleetwood. In 1987, they changed it to a 2.93:1 gear. A bit more acceleration, and it was actually better on gas as well.
 The Chevrolet powered Cadillacs used the 2.93:1 gear as well, right up to the 96 model. Cars with the towing package got the 3.23:1 gear.

 Mike