Hi

I have an 83 350 truck block 14010207 with dished pistons, the heads are 462624 castings with 1.70" intake and 1.5" exhaust valves.

I hope to find some stock heads which will perform better than the original stockers. Do some clean up of the castings and maybe some minimal porting.
This engine is in a 10000lb motorhome.

I would like to increase the torque and the horsepower a bit by swapping the heads, I can't reuse the current heads in the condition there in so this is a good time to do a bit of upgrading if possible, a better flowing head and positive valve seals.

I first thought of using 87-up truck heads but it sounds like they use a larger combustion chamber, I don't want to decrease or increase my compression ratio (have to stay with regular gas)

I heard someone mention here about using a 305 head with larger valves and that the smaller combustion chamber would work with the dished pistons.

Are there any heads to look for? Casting numbers and or vehicle applications...

Is it more expensive to buy remanufactured heads or to find heads which can be rebuilt and brought in to a machine shop to get done? What have you found?

Thanks
Mike…

 

Best heads to get would be Vortecs. 96-99 Chevy truck/van. Casting numbers end in 906 or 062. For a quick and easy upgrade, just get a pair off a wrecked truck, get the basic freshen-up work done to them (valve job), and throw them on your truck, as is, without further modification except maybe new valve springs. Your motor most likely has the infamous "929" cam; 194°/204° @ .050", .390"/.410". No mods are needed to those heads to accomodate that cam.

They will need an intake to go with them. Their intake ports are not in the same place as earlier small blocks; so "drilling bolt holes" will NOT be enough to use them correctly. Get a Vortec-specific intake. I'd suggest this one.

 

anything is going tbe better than those 624's of course, i would get rid of them ASAP

if you didnt want to go the vortec route which would require a special intake and other stuff or cant afford all that then you would be still lots better off with stock 70s castings such as the commonly found 993's and 882's and so on

junkyard prices determine whats going ot cost more or less than each other though

a set of good used gen i sbc heads that may need at least new guides and seals, or a pair of good used 060 vortec heads that may need the same possibly but will flow better in the end,

and so on


you may find this page of interest if you take the time to scroll down and browse around
http://www.purplesagetradingpost.com...fo/heads1.html

jut thought id say something

 

The newer TBI engines have 64cc chambers in them. They are not 74-76 cc like your current heads. They also build more low-midrange torque, exactly what you need to pull the weight.

I would recomeend a Crane 272-H10. I have one in the 350 TBI in my 1991 G20 van and often pull 5,000+ lbs behind it. The 1991 G20 only has 3.42 gears. It pulls hard from off-idle clear to 5,000 rpm with the stock torque converter.

906 or 062 vortec heads will flow the best out of anything else available, have small 64cc chambers and will burn more efficiently than the smog junk.

I have a pair of Ported Vortecs that I am about to put onto my 1983 G20 Van.

I would recomeend a 2 1/4" manifolds into a single free flowing 3" exhaust, this will boost torque in the low-midrange area, exactly where you need it.

A small 500-600 cfm carburetor or Q-Jet will help as well. With that much weight the Q-Jet will often cost you fuel mileage, because the small primaries do not flow enough to keep your speed up on slight hills and you are into the secondaries.

 

I would avoid ANY of the smogger castings such as 882 or 993, since those are essentially the same as the 624. In fact the 624 and the 882 were used interchangeably on 350s and 400s through the 70s. 993 was an earlier version of the same thing, the main difference being that they were mostly "heavy" castings where the 882 and 624 are "light" castings.

I would also avoid ANY TBI castings. Those include castings 187 & 193. The 193 is found on truck and Caprice 350s from about 87 to 95. The 187 was used on the TBI Camaro/Firebird 305, and is the primary reason you see most people on this BBS complaining about how slow their TBI 305 is. Take those off, put the TPI casting on, instant 30 HP with no other changes and no trade-offs.

People will try to pawn off all sorts of garbage as "early Vortecs", "almost as good as Vortecs", "just like Vortecs except [fill in lame excuse here]", "these [typical smoggers] are better than Vortecs", "202 heads", and so forth. Ignore the drivel and stay focused. Heads either ARE Vortec, or they are NOT Vortec. Either the intake ports are in the Vortec location, or they're in the early-model location (not Vortec). There's no such thing as "almost", "early", or any of that.

Besides the Vortecs, the next best stock castings would be the TPI 350 ones (083) or the TPI 305 ones (081); or the early 80s 305 heads, castings 416 or 601. You can pick up any of these from your local buzzard, or the classifieds on this site, or any number of other places. You should be able to come up with a pair of any of these for anywhere from $50 to $150. If you came across any of the old double-humps with bolt holes, those would be good too; but they tend to be huge $$$$$ because that's what EVERYBODY thinks they want, so don't spend any effort to find them, and they're no better for your purpose than any of the others so don't spend any extra to get them.

Also avoid the early 305 castings from the late 70s like 434.

 

I'm worried the Vortec wouldn't clear the big old Harrison A6 AC compressor I have, sounds like they are slightly bigger because of the taller runner design.
I think the 14101083 head would be my best bet.
Would the 083 increase my compression ratio too much for regular gas.

I found the 14101083 head by searching for a head for 87 350 Camaro it listed a 14101083 and the 14096217, is the 217 a good head also?

Engine 83 350 Converted to TBI
TBI intake modified for earlier heads.
1227747 ecm converted to flash chip.

Thanks
Mike...

 

Are you using 3" exhaust and stock cast exhaust manifolds?

I'm running factory cast exhaust manifolds with 2.5" tubes into a single big block truck muffler then it comes out of the muffler as 3" single.

My exhaust manifold is cooked in the area the tin covers the manifold to direct heat to the intake. the right side exhaust manifold looks like it's been in a forge to long:-)
The muffler that came with the motorhome looked like a Jiffy Pop popcorn dish after its been popped.

Mike...

 

If your MH is built off of the fullsize van chassis, the A6 was mounted just like it was on the same bracket that mine was. Mine worked fine with the TBI heads on it. The vortecs are the same height as the TBI heads. The A6 will clear fine. With a standard intake manifold, no air-gap, the bracket that bolts to the thermostat housing will even fit perfectly, etc. I switched mine to the serpentine setup like you would find on a 1992-1996 G-series van. Got tired of throwing the alternator belt every time I went over 5,000 rpm.

I know of another guy that is running the HT383 with vortec heads in a 1978 fullsize G10 van. Using the stock accessory bracket and A6 compressor. He posted under the name MWS on Chevytalk.com The A6 is a tough compressor, but really sucks the HP.

I have a little video coming of my ported TPI 305 headed, ZZ4 cammed 350 TBI with 3.07 gears in my 1983 G20. It MOVES.

I have my Vortecs ready to go, just need the intake.

I was running cast iron manifolds with the single 3" exhaust for some time. The manifolds had 2 1/4" outlets on them with 2 1/4" pipes into the single 3"

I have full lenght headers now.

The TBI is an excellent choice for moving that much weight.

I run TBI as well, on the 1983 it was an EASY swap, even had the VSS behind the stock instrument cluster to tap into.

 

My motorhome is based on the full size G-series Van GMC3500 Vandura with a 146" wheelbase.

I tried headers but they wouldn't fit. The right side of the engine compartment is very tight. The cast exhaust manifolds clear the frame by only 1/4"-3/8" The engine is offset to one side, I think this may be for the 1 ton dually drivetrain.
The exhaust manifold outlets on my manifold look smaller than 2 1/4" I'll have to look at different castings
Which headers did you use?
What year was the van you did the serpentine on? Did it have a A/C with the A6? I really can't stand the V-belt setup but I haven't switched because of the A/C. I don't know how the newer compressor would work on the older system and my PS pump runs my Hydroboost for the brakes. No boost no brakes very bad:-(
sorry for the multiple questions.
Thanks again for the reply

Mike...

 

My engine is offset to the passenger side as well. Very much so. Headers still fit though, I used Flowtech P#11500 easily. Did not even have to ding the pipes, fit right in place. I DID however have to remove the carbed fuel lines that were fighting for the same space as the headers.

The newer van used the DA6 which closely resembles the A6. I am running the DA6 and gave the A6 the heave ho. I used the hoses off of a newer van, forget the exact year. IIRC, it was a 1992 Astro Exact fit to the stock condensor and accumulator.

I have the hydroboost setup from the 1992 G20 on my van as well. From what I can tell the 1992 or so on G20s with towing package had the hydroboost as factory equipment.

 

Just posted some videos up on the net and linked them to this site.

https://www.thirdgen.org/forums/tbi/...ml#post3223730

This is just a dished piston 350 shortblock, Ported 305 TPI heads, ZZ4 roller cam, headers, duals, TBI setup with tuning.

A little extreme for your needs, but substitute the ZZ4 cam for something in the 206-216* range with about .450" lift and you will be going in the right direction

 

I liked the van doing the burnout best:-)

Any gains over my stock 160hp 80's smog motor would be great

My motor fits about the same as yours. thanks for the pictures.

Mike...