i have a 1970 cutlass supreme 350/ 4 barrel. on my build sheet the engine shows a qp, i read a article saying there was a qv,qb, anyone know what a qp stands for any help, thanks.

 

I just checked mine and mine has the same QP. My trans shows JL. It is a 350 turbo. I'm not sure either. All I know is that the 70 Supreme 350 had 315 horse. By looking at some of the other codes It looks just like random codes they made up???

 

i don't know i bought this car from the original owner, had 2 of the same build sheets under the rear seat, the article i read was in muscle machine, the engine in mine should have 310 horse, with the 4 barrell, mine only has 54,000 original mile on it.it said the qb engine had a hotter cam and only 531 were produced that year.

 

Sounds like a nice car. Your right 310 HP. I just looked at a dealers brochure and it only shows one other 350 with more horse W-31 with 325. Maybe you could order that in the supreme and is the qb engine. Mine also was a one owner. I found 3 build sheets but only one was ledgible. Mine currantly has just over 170,000 and the engine has never been out of the car. Was yours built at the Linden Plant?

 

Hello, my service manual and online sources show (4) 350 4bbl engine codes. Three are L 74's QV SMT which I believe is the hotter cam mill, a QN for AT wo/ AC, and a OP for AT w/ AC. All three were rated at 310 gross hp which doesn't mean to much, but the manual trans engine with the hotter cam (#393858) should produce more horsepower. The hottest 350 Rocket was the W31.http://oldsjunction.classicoldsmobil...ofcam.htm#Cams

 

Mine shows L-74 and is Coded QP. So I guess it doesn't mean too much.

 

If the codes stayed the same a QP in '71 is a 350 4 barrel with air conditioning for a Cutlass Supreme.

Allan

 

mine was sold in phila pa on germantown ave , factory buckets,console,am radio,to the 1st owner, i believe it was built in the same plant, also anyone running hei in these cars, mine runs really good, but would like to switch it over,and does it make a major difference, also what fits in there good, mine is a a/c car,i want to make sure i have clearence with the fire wall, just ordered a quater skin thats getting done,

 

I put an late 70's HEI in mine. Plenty of clearance. As far as performance I never noticed much. Most any will work you just may have to play with springs and weights if you want optimin performance.

 

Don't get me wrong, the Olds 350 is a good performer with allot of potential. The ratings pre 1972 were somewhat misleading as installed in the vehicle. 310 gross HP converted to net HP is about 230-240hp maybe a little more, a powerful engine in a mid size vehicle. Mid 70's V8 engine strugeled to get this with as much as 100 cu. larger displacements. And some of those powered cars to 14 sec. 1/4 mile times. The best GM V8 IMO...

 

mine runs really well, doesn't tap,smoke, had the carb rebuilt, but when it was on a scope the gear on the trans shows wear, runs strong,still spins the tire,-peg leg-rear, i figure hei or should go wit a stock distributer with pertronix? don't know what will run better. not gonna do a rebuild yet, it runs that good.

 

From the 1970 CSM engine ID chart:

QP is optional L-74 350-4V, 10.25 CR, AT with airconditioning in these carlines.

3200 F85

3600 Cutlass

4200 Cutlass Supreme

4800 Vista Cruiser

 

thanks i appreciate the info.