Thread: 350 or 383?? Guru advice needed!!

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thanks for the advise, im leanin more twards doin the stroker, but if i do there is soooo much more potential and i know im goin to go wayyy over what i want to spend!!

Originally Posted by crazy350

thanks for the advise, im leanin more twards doin the stroker, but if i do there is soooo much more potential and i know im goin to go wayyy over what i want to spend!!

Don't we all

Welcome to CHR

As mentioned – we thrash this topic often. You didn’t say what you are planning to use this engine in. It makes a differences i.e., a ’32 Ford coupe or a ’76 ¾ ton 4x4? If you’re looking for torque to come on low and strong, a 383 may be a good bet. If you want to have 400+ horsepower for your boulevard cruiser, the 350 may be a good fit.

First and foremost - find a good machine shop where you can talk to the person that will be doing the work.

Since you purchased a re-buildable engine for next to nothing, you’ve got lots of options! If you would like to stay with iron heads, I’d opt for L31 Vortecs, casting number 12558062 or 10239906. They were used on '96-'99 Chevy trucks with the L31 5700 Vortec engine and are readily available in wrecking yards and on Craigslist / eBay (make sure they’re genuine GM heads – not knock offs!). These heads use rail rockers, so get the rockers with them if you can. These are some of the best flowing production heads that Chevy ever made. A good machine shop will be able to pin the studs, install new seals, and perform a 5-angle valve job. You can buy Comp Cams drop-in beehive valve springs and retainers that complement your cam and you have a great set of heads for well under a grand.

A good cam would be Comp Cams part 12-246-3. This is a flat tappet cam so you’ll need to pay attention to break-in, but it’s a proven performer that won’t break the bank and will give you great performance on the street with a lot of mid-range snap. It will have a bit of a lope but not to the extent that your friends will wonder if you have a flatulating elephant under the hood.

If you want to go aftermarket heads, there’s a virtual plethora of choices and several here will chime in with AFT, Brodix, etc recommendations.

I like the Edelbrock Performer RPM Vortec #7116 or Performer RPM Air Gap Vortec #7516 intake manifold. These are Vortec specific manifolds that require a square bore (Holley or Edelbrock) carburetor. Stay with a 600 -650CFM carburetor.

The Vortec heads are 64cc. Use a piston that gives you a static compression ratio between 9.6:1 - 9.8:1. Work with your machinist here. KB (and others) has an offset dish type piston in a D-cup configuration that provides a nice crown to complement the Vortec head configuration. Ask your machinist to cut the block decks to 9.001" for a zero piston deck height and use a 0.039" or 0.040" compressed head gasket. This should allow you to run premium pump gas without detonation – but be prepared to need some octane booster depending on the quality of your local petrol supply.

Buy some Hooker 1 5/8" long tube, equal length headers that fit the car and route through Flowmaster 40 series mufflers – I really like ceramic coated for looks, longevity and heat dissipation.

In addition to the above – make sure you get a good new oil pump with a welded or otherwise firmly affixed pickup. Miloden kit with pan, windage tray, bolts, one piece gasket, pump, and pickup is a good investment. Go with a stock 5 quart pan – resist the temptation to go with a deep pan unless you know you’ll have lots of ground clearance.

New lifters – Comp Cams, new timing set – double roller from Summit is fine, new HEI distributor, new water pump, and good gasket set like Felpro.

Others will add their two cents – this is what came off the top of my head.

Again – welcome to CHR
Glenn