trevor s

My 73 was owned by an old lady. Thecar has 72,800 miles on it andis in excellent shape just needs paint and brakes but the 350 could use a kick in the pants. It runs perfect with no noise, abnormal smoking etc.
I was thinking 72 7a heads edelbrock performer cam and llifter kit performer 3711 intake, rebuild the q jet and a set of headers. Any thoughts on the 7a heads? any problems I may have.

oldcutlass

Welcome, we do like pictures. That should be a good combo for an out of the box improvement. Most Olds heads flow the pretty close with a bit of messaging.

trevor s

would it make sense to replace the heads or spend some money at the machine shop with the #8 heads? Thanks!

cutlassefi

Do the 7a's and there are better cams out there than that generic Edelbrock.

coppercutlass

I ran a 73 shortblock with 72 7a heads. Compression was 9 to 1 . I ran a comp 260h cam. With an edelbrock intake and 60o cfm carb, full length headers, hei dist. X pipe exhaust, 2300 stall and 3.73 gears I got it to run 13.86 when the car was all steel still. 13.71 w fiberglass fenders and hood.

trevor s

thanks! for rear gears what ratio could / should I use. Right now they are 2:56 or 2:73's? I don't plan on racing it so I'm not so worried about a posi and I was going to keep the original th350

cutlassefi

3.42 seems to be a good combo for a mild small block.

trevor s

so a 3:42 will fit the stock carrier. am I right in thinking it's a 2 series???

oldcutlass

Yes, and if you may consider going to a Performer RPM manifold depending on your cam choice.

Olds1971

What all motor work did you have to do as far was boreing it, lifts/rockers ect?

coppercutlass

Short block was std. Bore freshened up. Heads where freshened up. Both great cores . Rockers where stockers. Nothing fancy just the proper set up and matching of parts . I also ran manual steering to free up hp. The car went from 14.0 to 13.86 with the addition of an x pipe. It was a solid 14.0 car up until I added the x pipe.

Olds1971

Not to high jack this thread but copper maybe you can give me advice. I have a stock 72 olds 350 in a four dr 83 it runs 10.8 at the eighth hoping to break low 9 is it possible with a stock block with no boreing ect

1970-W30

I don't believe the 3.42s will work on the 2.56 or 2.73 carrier. It will require a different carrier, or a spacer ring.

coppercutlass

The key to my combo was the 73 shortblock with 72 heads since the 73 block has a smaller cc dish with a shim gasket the compression is right around 9 to 1.

Olds1971

Whats the compression on a 1972s?

coppercutlass

I think it was advertised 8.5 to 1 but closer to 8 to 1.

Olds1971

how to you change compression? Would it make much improvement going from 8:1 to 9 ;1

DoubleV

Better pistons, decking block, milling heads, thinner head gaskets or any combination of those things.

Not much, but the higher CR opens up the door for a bigger/better cam which would then make a noticable difference over the weak stock cam.

Olds1971

Can you do a couple of those or all to change compression?

coppercutlass

It comes down to many variables like head cc, piston dish cc if it has one, how far in the cylinders they sit at tdc, head gasket thickness. If you are planning a build knowing what cam will work with the mods you are planning to make or are already running will determin what you will need to do to have the engine run properly.