just looking to gain all the info and knowledge about this engine I just put it in my 86 olds cutlass, would like to get help putting a plan together for a nice build on it but needing direction. thank you all

 

I am looking for the flaws of this engine and the benefits and features of this engine.
also its hp compression ratio head size everything will help, what are the factory cam specs for this engine? also and advice to start a build what works well what can i do thats going to get the most bang for a budget build.

 

What if you were to procure a copy of the factory service manual and read thru it?

I take it you are looking at building something with 1972 issue "7A" heads?

How much were you planning to spend? - full rebuild gets past $3k real quickly
what do you have to start with?
what is the goal?

 

If those heads are good platform to open up then yes thats just whats on it.
as for the manual i have been looking, and the goal is a street/strip car cruise it around having a little fun and take it to the track on the weekends.
I have made a few changes but would like to understand the changes i made a bit better. I dont really understand the timing and total timing thing, although If i understood correctly it should be close to okay. I did install the Mr. Gasket weight kit with the lightest springs.
I dont feel Like its spot on though.
I really would love to get it running on all cylinders as best as it can before altering so I have a bottom line. btw I just put a Chevy TH 350 non lock up in it with a street strip kit in it.

 

Oh and to answer the most inportant question lol I am most certainly building on a budget a tight one.

 

The flaw with that year engine is the pistons, they have huge dishes resulting a very low compression ratio, around 8 to 1. That limits cam choice, etc. The cheapest way to go is to find a 73-76 block in decent shape, rering it, mill the 7a heads a tad, end up with close to 9 to 1. Or, spend some $ on yours and bore it and get better pistons.

That said, properly tuned, it should be fun enough in your G-body in stock form, simply from the added cubes and torque.

 

I have a combo I was gonna build. I got the 14cc pistons , #4 heads which have less volume than 72 heads . I got the block heads to put you in the right direction for some useable comepression. Depending on which way you go getting 9.25 to 1 compression from this set up is easy. Block needs a hone for ring seal , crank needs a minor polish . The heads will need a valve job and guides possibly . I will let everything go for 300 obo . The block you get has studs and straps on the mains . Not needed for a mild build but nice to have. Shipping is usually about 175 through fastenal. Just putting that out there. The #4 heads usually bring in 200 alone for cores if not more.

 

As captjim said, the heads are good but the compression ratio on the '71-'72 engines was very low due to the huge dish in the pistons. Change those and you can make some power.

The camshaft was very tame:
.400"/.400" lift
186°/202° duration @ .050"
250°/264° advertised duration
108° intake centerline
109° LSA

Below are the '72 350 engine specs for the various configurations:

Engine Carb Exhaust HP @ RPM FT-LBS @ RPM
- ------ ----- ------- ----------- ------------
350 2-bbl single 160 @ 4000 275 @ 2400
350 4-bbl single 180 @ 4000 275 @ 2800

350 2-bbl dual 175 @ 4000 295 @ 2600
350 4-bbl dual 200 @ 4400 300 @ 3200

 

thats all really good to know and a good starting point. i really dont want to get another block to start with. I would like to just use what i have and get the most out of it. I also have a 150 shot of nitrous I would like to run as well so please keep that in mind as advising me through this build thank you all

 

how much is a tad and would i need to go to an adjustable top end?

 

Not sure a budget build motor and NOS would play well together - not for long anyway... Maybe a 455 swap might be more appropriate for your purposes?

My '72 350/7A is a straight 9.5:1 CR build which includes a Howards street performance cam kit, flat-top pistons, E-brock 2711 intake, 800cfm Q-jet built to engine specs. Stock rocker train (albeit all new Comp Cams set).

Also backed by a TH350 with 2300-2600 stall and a 3.08 posi rear. A 3.23 or (numerically) larger rear gear would really add a kick to the seat but I road trip my ragtop so the highway RPMs more of a concern. I also run A/C and power brakes so cam specs are reasonably hot but still well suited for street use.

Just some other options for thought...

 

would i need an adjustable valvetrain if i use a larger cam than stock?