350 mild redo questions

[RCPeters]

I have waited many years to do a mild rebuild on a 350 and now that the 87 Iroc (not a fan of TPI) of my boys is running I actually have some time for my project. I am hoping for some help from y'all .

My 72 has a 350 4bl with a little over 200K miles. It runs very strong for a stock motor. The 350 was gone through at 140K.

I have read a bunch of the strings from the members. I however can not yet connect the dots. Here is what I am thinking:

1. Keep the block Crank and pistons in tact does this make sense?

2. New Cam , is Summit Racing a good place to help me speck a cam in.

3. Rebuild heads or new? Standard Valves or ??????

4. Keep the old intake ?

5. Keep and rebuild that Rochester Q jet or Holley?

6. Headers and exhaust, Does size matter?

7. Electronic ign? MSD or keep standard ?

8 Did I miss something?

 

I would like to get a nice sounding peppy Monte. It will be a driver not for the strip. Something for my boys and I to tool around town in.

 

I am sorry for the elementary questions.Any help would be great!

 

Ron

[kc8oye]

Why would you not be a fan of TPI? Since it's better then a carb in every respect?

 

ok 1) Define "Gone through" did it get new pistons then? if not, it's DEFINITELY time for an over-bore and new pistons.

2) summit racing cams are pretty good for the money. You might consider a Lunati VooDoo cam instead.

3) heads are going to depend on what you want to do with the engine (Same with the cam) if you are just looking to freshen it up, stock heads are fine if they are in good shape (they will need valve guides and a 3 angle valve job most likely) if you are looking for power, consider GM Vortec iron heads.

4) what is the old intake? Stock iron? throw it away. Get an Edelbrock Performer RPM (With the airgap if you want to make power)

5) carb again depends on what you are trying to do. mostly stock street cruiser.. keep the qjet. looking for power holley.

6) street only.. keep the manifolds, they hurt power, but are far less trouble to maintain. If you want any power at all, full length long tube headers. Size isn't too critical.. 1-5/8" primary is about all you will find for small blocks. 2-1/2" or 3" collectors. There is a company out there that does CNC porting on iron manifolds and can supposedly make them flow like a header....

 

7) MSD all the way. #8360 distributor with a Blaster 2 coil. i'd highly recommend a multi-spark box. (6AL, 6AL-2). also look into the MSD E-curve distributor.

[RCPeters]

Thank you so much. I appreciate your time and response.

I bought the car from a guy who kept every receipt and found that he only went through the top half of the motor. Cam and Heads. So I guess I am in the market for a set of pistons. The 350 runs pretty well however if I improve the top end I am sure the bottom will take a beating and fail soon. This now opens up a few new questions. How much to bore over ? Will I know this before I take it to the shop? I have read some blogs that suggest that I will need to choose a piston prior to the bore? Flat top or domed? Forged or ??? Regrind the crank or replace (may be a poor question) I assume you replace this and what should I look out for? I have seen them from $150 to $700. I would hate to put a nice package together and have the wrong foundation!

 

On to your other questions. The intake is original . I will go with an Edelbrock performer. Not sure if this one is available for the non vortec heads. What makes the Vortec heads better than the stock? I assume I will need to match the intake with the style of head I choose, vortec to vortec...

 

Thanks in advance. I am now going to go empty my change bag and see what I can afford!

[kc8oye]

My personal recomendation is keep the overbore as small as necessary to make the cylinders round again. but finding odd size pistons nowdays is kinda tough. .030 is usually a good number. .060 is the absolute limit for a smallblock unless you want to get into sleeving cylinders.

 

I really really reccomend you run Forged pistons.. they're more durable, and if you ever get the urge to throw a little nitrous at it, they will handle it just fine. if you are really sure you wont' ever play with the giggle gas, the hypereutectic pistons will do you just fine. I used SpeedPro Power Forged pistons in my 350.. cost me $300 for the set from Summit Racing. they have the nifty anti-friction coating on the skirt too.

 

 

domed, flattop or dished it going to depend entirely on your heads. flattop with vortec heads would leave you with a pretty high compression ratio.. somewhere in the mid 10's I believe, but I could be wrong. you will want the machine shop to inspect your block and tell you how far they need to bore it. then buy your pistons.. a good shop will custom hone each cylinder to a specific piston for the best ring seal.

 

Don't waste your time with the basic "performer" it's only mildly better then your stock iron intake. but then again, unless you want to run a carb with an electric choke, the "performer RPM" may not be the hot choice for you.

 

since you aren't racing, regrinding your crank if it needs it is probably the best option. you really don't need to spend the $$$ on a forged crank.

 

The vortec heads breathe WAY WAY WAY better then anything GM has ever used in production except for the LS heads

 

but you will need a special intake and different valve covers (center bolt)

 

if you are just building a street cruiser with the occasional stoplight dragrace in mind. your stock heads with some flattop pistons will problaby work just fine.

 

I used stock heads but i think they are from '73, all I did was a little exhaust port matching on them and with flattop pistons and a mild summit racing brand cam, (214/224 @ .050) I'm making around 300hp and running the 1/4 mile in 14.2's...

[cbolt]

Instead of guessing why not just get some advice ahead of any purchase from whatever machine shop you decide to use to do the block? They can tell you the overall condition of the cylinders, block and the rotating assemblies to help you make an informed decision as to what work would need to be done to your existing parts as far as how much to bore or if your crank needs to be ground as well as whether or not you need to replace any parts like the pistons, connecting rods, crank, etc. Assuming you are looking at a mild rebuild it would be a safe guess that you don't plan on making a ton of torque or horsepower but would like the peace of mind to be able to open it up from time to time without worrying about something breaking so if new parts are required pick something designed for your particular requirements and the people at either Summit or Jegs will be able to assist you over the phone. In other words you don't need domed racing pistons if you are planning on running pump gas and driving around town. That would be expensive overkill. One more thing you need to consider is matching any parts you buy to what you are trying to build. You want to choose an intake, cam, heads, carb, pistons that will work well together in your desired rpm and horsepower range. Again my suggestion would be to ask the people at either Jegs or Summit if you are uncertain when selecting these components. They have been very helpful in my experiences in both helping to select matched parts and keeping within a budget. Everyone has their favorite aftermarket companies and combinations so I will refrain from advising a particular brand for anything on your car, that is entirely up to your tastes. Whatever you decide to do remember to file away all those reciepts and document all the specs for future reference and have fun! I always have a blast selecting parts and building an engine.