Oldskool84

Thx Oldcutlass

MDchanic

Nobody means to imply that he took the big box o' parts and shook it up, only that someone did, but that it's now his job (and not his mechanic's) to undo the damage.

As Joe said, read, read, read, then start working.
Or, as the carpenters say, "Measure twice, Cut once."

Get some books, as suggested above, including Mondello's, Bill Trovato's and the Chassis Service Manual, and take your time to do some slow, relaxed learning, read everything you can find on the subject on these boards, concentrating on posts by the likes of Joe Padovano, CutlassEFI, 380Racer, and several others, and only then begin to chart your course.

First order of business it to learn what you have.
Are the pistons original (Is the compression the original 8.5:1, or has it been increased or decreased)?
What are the cam specs?
How are the carb and timing set up?
What kind of transmission, and are there any modifications to the trans. or the converter?
Once you know where you are, you can decide where you're going.

- Eric

z11375ss

I agree 100%. The best advice I've seen though is to put in a smaller cam, switch the carb and get it tuned. I bet that thing rips the tires off for a hell of a lot less cabbage than changing the motor.

Oldskool84

Ok thx

z11375ss

When I was a young man I had a small chevy. I changed the cam to a big one and the car ran like garbage, Same goes for changing to a single plane intake. The car went slower! Having the right parts that work as a unit is the most important thing. I found out the hard way that bigger was not necessarily better. You'll get this baby sorted out. Keep posting with what you're doing. There are guys on here that have forgotten more than I'll ever know. They are great guys and a great source of info. Remember, no question is considered stupid. We've all been where you are. Good luck! Jim

Oldskool84

Thx for the words of encouragement jim.

nsnarsk65cutlass

Brutal,any 455 even a smog 74-76 will do better than one that won't run or is built with incorrect or miss matched performance parts.

Oldskool84

Ok, so can u guys give me a little guidance on worth while literature and/or instructional dvds about building/tuning the 72 olds 350? You guys have given me a great start but in order for me to do some homework on my own i need a reliable source of info.

Oldskool84

Also, if i was able to find a 455 , what mods would i need to do to make the swap ?

oldcutlass

How about we try and make your 350 perform first. I would be willing bet that your tune up settings are way off.


Do you have a timing light, vacuum gauge, tach, and some basic hand tools?

joe_padavano

Virtually none. The only external difference between an Olds 350 and 455 is the deck height. The exhaust manifolds need to be changed to match the taller deck. Pretty much everything else bolts up from the 350. Depending on what radiator you car currently has, you may need a bigger one.

captjim

I have never actually swapped in a BBO, always stuck with "little brother". Does the extra deck height affect any of the brackets? Seems like it would IF they bolt to the intake. Also, any issues with front springs?

joe_padavano

It depends on the year. For the 1968-76 model years, the brackets have two sets of holes to accommodate both BBO and SBO deck heights (where it matters). The weight difference is on the order of 50 lbs or so. I've swapped a few BBOs into SBO cars and not changed the springs - in fact, I often cut the front springs to lower the front end.

droptopron

Did the car run bad when you bought it or get worse over time? If it ran good when you bought it, what has changed? Someone mentioned dished pistons & 8:1 compression. Do you know if the lower half has been rebuilt? if so, orig pistons could be gone.

cadillac kevin

I would not ditch that engine just for those problems. they sound like the issues you get with a poorly modified engine with mismatched parts that isnt tuned. As suggested, I would try putting it back close to stock. ditch the cam for something closer to stock specs. Someone probably put in that cam because they wanted the "sound" of a hopped up car, but it will give you driveability problems. I'd also ditch the intake, carb, and ignition setup you have. Go for a basic dual plane intake, a GOOD holley/ edelbrock carb, and a factory HEI unit from the mid/ late 70s (pre CCC). It will be much cheaper and much less of a PITA than going to a chevy engine (did that in my caddy that had a dead 307 olds. it was a headache trying to find all the piddly crap to make it work, and that was with being able to source alot of the typically nearly-unobtanium misc parts at the junkyard). "Just throwing in a small block chevy" isn't exactly as easy as you would think it is. De-mod that olds 350, get a competent mechanic to tune it, and enjoy the great engine that olds made (having driven vehicles with engines from every GM make, I prefer the smoothness/ refinement of olds and caddys)

Lars

There's a book called How to build horse powet by david vissard. This will give you some basics. The ultimate olds book is by bill travato. A chassis service manual is also a good read.

Oldskool84

Thx Lars!