is it a 2 bbl. or 4 bbl.??? if it's a 2 bbl. just rebuild it & do the hardened valve seats for unleaded gas. Cam & lifters etc. aren't going to do a thing for it IMO Pete

I agree with the "go mild" thoughts. In my opinion, going "all out" on a 283 only happens with lots of RPMs. Like the old DZ302's. They made pretty good pwer, but they were never going to be a torque monster. If you don't mind things spinning at 7000+ RPM's, 283's (and 302's) can make some amazing horsepower, but with that set up, you better have a standard or a high stall converter or it won't get out of it's own way off the line.

I had a friend who drag raced a 283. He routinely took her to 7500 PRM and dumped the clutch to break 'em loose for a burnout. I closed my eyes and grimaced every time he did it. Regular launch was at 7000 RPM.

I'd be wary of the 2.02 valves as well - unless you plan on spinning it to well over 6500. I would think a good set of vortec heads with 1.94 intakes would flow as much and probably give a little more low to mid-range torque. You can probably pick up a set with 64 cc chambers for what it would cost you to rebuild the 283 heads (with hardened seats all round).

Just an opinion...

ad a mild cam, I overcammed my ol 283 with a 300 hp 327 cam, 4 bbl and headers. no torque , but it did turn on at 3000 rpm. pulled great up to 6500 rpm.

WAS not a cruiser engine , I ended up adding gears and a converter to get it out of the hole.

if i was to change my heads on my 283(so i could run pump gas with no additive) , what would i look for? what year? How and can you just put hardened valve seats in?  I need a reliable engine, its just a cruiser. OR...... should i sell this all original 283 (36,000 miles) and put a 350 in just so i can get parts easier? I am moving to Mexico and i want to be able to fix it easy enough if i have to.

-- Edited by 59poncho on Tuesday 6th of July 2010 10:33:31 PM

My suggestion for heads on a 283 would be a set of rebuilt 305 heads from the 80's. The reason why is that they offer more compression than most stock GM heads and they are small valves which will help the 283 make some torque. They also have hardened valve seats for unleaded fuel and are readily available at very reasonable cost. These are really great heads for a low revving street car IMO.

The vortec heads are available from GM Performance parts - brand new assembled, complete with valves, springs etc - for about $300. These are a steal of a deal as far as I am concerned, 64 cc chambers, 1.94 intake valves and I believe them to be the best flowing heads out there short of high dollar CNC specialty heads.

https://store.gmperformanceparts.com/store/SelectCat.do?catId=1738&prodsFound=11&redir=true&category=Cylinder%20Heads
See part number 12558060 and click on "See Dealer Pricing" 

Check out what it would cost you for a rebuild. With 36,000 miles, you shouldn't need new guides, but I expect the hardened seats are going to be about $10 to $15 per valve (NOTE - Wild a$$ guess on pricing - haven't doen these in many years). To do this, they machine out the old seat and press in a new stellite (hardened) seat insert. The valves will need grinding and the new seats need to be ground to match. I honestly can't remember if you need to replace the valves or not (for the higher temps). With only 36,000 miles, I would be surprised to see more than about 1.5 thousands wear on the valve stems, which would normally be OK.  If your milage is hgher, start adding in some valve guides and replacement valves.  You quickly end up at well over $300.

Three disadvantages of Vortec heads.

1.  They require a Vortec head intake manifold and gaskets.  The bolts to the heads are different.  Edelbrock makes them (as 67SD396 says, I'd go with the Performer not the Performer RPM nor the AirGap).  Holley also makes intakes for the Vortec heads.  Or you could get one from the junk yard (I cannot remember for sure, but it seems to me early 90's GM trucks with carbs??  Anyone know for sure?).  I would expect to find one for less than $150 but it would require some shopping.

2.  They use a centre-bolt valve cover.  You can get after market ones or get them from the junk yard.  Or if you want a stock look, they make conversion kits to let you use traditional edge-bolt valve covers.  I've never used them, but I have seen them & they seem to work.

3. Out of the box, the Vortec's are limited to about 0.460 inch lift at the valve.  If you're going higher, you'll need to check clearance between the valve guide and the bottom of the spring retainer/valve seal.  They may need to take a little off the top of the valve guide - or if you're really going high lift, you will need special springs to avoid bind.

The low volume 305 heads suggested by 67SD396 would be a good choice too, except you'd probably have to buy some, then have them rebuilt anyway... 

For cams, I suspect you would want less duration & overlap than would normally be spec'd for a 350.  The spec's provided by davelacourse look like a good starting point.  I have had good driveability fram the Crane "towing" cam line.

I would pull the caps off the crank and have a look at the journals and bearings.  You can get some Plasigage (likely from Acklands or similar?) for relatively cheap and check clearances easily.  If the journals are tapered, scored up or clearances are excessive, then your crank should be re-ground and new bearings installed.  If the journals & bearings look good and clearances are good, I would not recommend re-grinding. 

Hope this is helpful.  Have fun, be safe.   Wes 


-- Edited by 66 Beau on Wednesday 7th of July 2010 11:59:23 AM

I would think a 200R4 would be a great swap for a 283. Nice low first gear, and the overdrive on the highway. Dimensionally, it's a bolt in swap. Need to move the trsns x-member back to the TH400 bolt holes (for vehicles that had teh TH400 as an option). You should be able to get a good used 200R4 with a 30 day warranty from a wrecker for about $300. I suspect it would last for years behind a mild 283 as long as the TV cable is correctly set up.

The TH350 also has a lower first gear doesn't it? Anything would be an improvement over the powerglide - IMHO.

59poncho wrote:

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so what your all saying is... i should put the th350 in that i have sitting in the garage, and the heads from my 80's 305 i have sitting there also??!! And to answer Carl S. the altitude is 5800 above sea level. Thanks for all your suggestions, this makes it sooo much easier to figure out what to do as i dont have alot of time till we move. And yes your all invited!!

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Wow 5800 feet above sea level, you must be living on a mountain.   How far to the ocean?

 

66 Beau wrote:

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jmont64 wrote:

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Wow 5800 feet above sea level, you must be living on a mountain.   How far to the ocean?
 

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Gee, I'd guess about 5800 feet!

j/k

 

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That would be straight down, wouldn't it?

 

oh, and its maybe a 2 1/2 to 3 hour drive to peurta vallarta on the pacific ocean

I like to balance the rotating assembly after rebuilding, but tend to believe it's usually just an insurance (unless I was building it to rev beyond the original redline). If the engine ran fine before, and you haven't changed any of the rotating assembly, then I tend to think the balance should be unnecessary. If all you've changed is the pistons, they're usually well matched so it shouldn't change the balance. (Though many people do check the weight of the pistons coming out and those going in to make sure).

That said, if the original balance was borderline - meaning it was just within spec - changing anything could put it out of spec - which is where the 'insurance' factor comes in.

I wouldn't expect balancing the rotating assembly to produce a smoother run though. If it's unbalanced enough that you can feel it, I don't think it'll be running for too long... A well balanced assembly should reduce wear and tear, but again, I would be very surprised if you could feel the difference - at least up to the point where it came apart.

Anybody else have an opinion on balancing a rebuild?

I swapped out my powerglide for a 4 spd OD. Best improvement you can make IMHO. Lower first gear, and it cruises at less than 2000 RPM at freeway speeds. Makes a big difference at both ends.

I've been watching this thread.
I've heard beforehand that a 283 isn't the type of engine that is really feasable to "hop-up", besides some minor tweaks.
From what I'm hearing here, it seems the case.

I am interested more in the PG to TH350 upgrade.
Is it a bolt on upgrade? Do you have to change any externals (cross member, linkage, etc)?