The Stovebolt Site Forums The Shop Area Engine Shop Why not more 302s ?

I see a lot of sissy 235s but not many GMCs. Why is this, 302s are not hard to find. I wish I had more company. I hate going to a parts store and having to argue whether what I really have is a bored out 292 or some other engine that doesn't exist. From what I understand, Nick Arias is going to end up making the whole @$#%^ engine available. How about it guys (and gals).
Jason

You can get a short-block for around $800.00+/-!

Jason,

I think "not hard to find", as you say is relative. Sure they may not be hard to find in your area but in a place like, say, Georgia they are almost impossible to find.

As to why not more 302s, I would guess that build cost plays in to the picture almost as much as availability. The price that the few manufacturers of performance parts for the 302 (clifford research, Langdon, etc.) are absolutely ridiculous (to me).

The newest GMC 302 is still going to be several decades old. Any one you find has to be thoroughly examined. After you throw out those than are non-rebuildable, then you must go through the monumental task (and expense) of building it for high performance. After the upgrade (and several thousand dollars) later you have an engine that can still be blown away by a small block 350 at 1/4th the cost.

I hate to come across "anti-stovebolt" because I'm obviously not; It's a tough economy and people are using their dollars more wisely. And I believe that more people these days are thinking their projects through and assessing the costs before they begin work. Then the more economically sensible (and more powerful and versatile) small block v8 gets thrown in. Either that or a 292.

Just my .02 :confused:

It's probably economics as much as anything. A GMC has always been more costly to rebuild than a 235 and performance parts are available only through a couple of aftermarket niche suppliers. $600 for Venolia pistons are a bit steep for most folks. Building a 302 Jimmy with all the right pieces can eat up as much money as big block V8.
Plus you almost need to have another GMC core engine to use for the oil pan, flywheel etc which are too massive to use as is.

As you mention, the 302 GMC engine is not familiar to most parts sources - it was a heavy truck motor only, in production for a relatively brief period (1952-1959). Not hard to find? Well maybe not in your beautiful state of South Dakota, but old junkyards are disappearing fast in many parts of the country. Finding one with a head that's not cracked can be a challenge too.

The 302 is a great motor and can make some big torque, but for most Stovebolters it's probably hard to justify the cost and extra work.

And you still have a four bearing engine, where with the 292 you have seven.

True, but they were great engines (even with 4 mains).You can also get a NEW 12 port head for the 270/302.

You're right that it is a good engine. We had them in some 6x6's for fire trucks. But how much does it cost to build one? And how much is the 12 port head? I would like to have one, but am going to go with the 292 due to the cost and hassles of the 302. I just someone would produce a cross-flow head for the 292.

The 12 port head starts at 2800 and goes up from there!Remember,,,this is for performance!!!
Aluminum valve cover is 200 and the side cover is 150.
.I would like to just have a stock engine with a few upgrades!

Anyone building up a GMC engine,especially a 302, must become an expert on all the early GMC inlines. You have to know what parts are interchangable and be creative about moving parts from one size engine to the another to get the setup that you want.
As far as performance parts, I agree that there is a VERY small group of people that sell the performance parts and if performance is your goal you need to accept this fact and be ready to pay their prices.
If a reliable stock engine is your goal, your local parts house has many of the parts(internal stuff i.e. lifters, seals, gaskets etc...)you need. If the college punk at the local parts counter can't find the 302 engine in the catalogs, try telling him you have a 270 in your '57 GMC 1/2 ton P/U. The parts such as seals and gaskets will all be the same and the parts dude will be able to find the 270 easier because he was looking in the light Duty truck book to begin with. Parts people seem to relate better to 1/2 ton stuff better than the Heavy Duty vehicles for some reason.
When you are at the auto parts store you will need to ask for some things by vehicle application and some things by engine application. Example: If you are putting a 302 in a 47-54 GMC p/u don't go in and ask for the radiator hoses for 302 because the hoses you get will be for the 2-1/2 ton truck and because the radiator was farther away from the engine in these trucks, your hoses will be WAY to long. Just tell the punk at the counter you have a '52 1/2 ton P/U with a 228. The water pump is the same(pulley width being the only difference) on all 228,236,248,256,270, and 302 engines so the determining factor is what size truck the engine is pulling around.
Don't forget Uncle Sam. In 1952 thousands of GMC 6x6 2-1/2 ton trucks were built. Many of them now sit in junk yards across the country. Each one had a GMC 302 andthe 6x6 trucks before '52 had the 270. Now..... I know that alot of the external stuff is different but lets say you needed a camshaft, head, crankshaft, connecting rods etc. for your 270 or your 302, your all set. Heck, even the military block will work with a few easy modifications.
There are several companys that specialize in GMC 6x6 trucks and will sell you all the parts you need for your 302 and a lot of it is NOS military surplus. Memphis Equipment Company is one in Tennessee-not to far for those in Georgia Phone: 901-774-0600 (they even have a website)
Three more words: eBay, eBay, eBay.
Lots of people are selling surplus inventories and the deals are good. Email the sellers who look like they are selling NOS surplus parts and ask if they have the parts you need(the same simple way as you did with the guy at the auto parts store). You will get lots of negative replys, but the one time you find the parts you need will make it all worthwhile. Buy old parts manuals so that you can tell if the part number in the auction description will work for your application. You must assume certain things to get what you want also. Lets say a guy has a crankshaft pulley dampener up for auction and and after looking up the part number that he gave you in your '55 GMC parts manual, you determine that it is for a 248 engine. Will it work on a 302? Of course!! Because you are the savy GMC expert and you know that all the crankshafts have the same diameter on the front. GMC was a master at interchangability!!!!!

Building any inline is going to cost money but you can make it cost less by using available resources and being savy. Some will find that the thrill of the chase makes it all the more fun.
Hope this helps all those out there on "the hunt".

I appreciate the replies. I don't really agree that having 4 main bearings is an impediment, BB chevys only have 5 and the forces on them are much higher. Is the bottom end really overloaded? In addition, breaking up the crank to fit in all those bearings means a thinner crank which may not be as strong. But that don't seem to be the reason why most people aren't using 302s. You don't have to hop them up. You can leave tham stock at which point you still have plenty of power and minimal expense.

To add to the good points 52gmc6 wrote, the military surplus places are the best places to check. In addition to Memphis equipment there is Boyce Equipment. But don't forget that there are lots of surplus trucks in smaller surplus outfits that have 302s needing a good home. I know of about six that are available locally and there are even more in Rapid City.
jason

I'm still with ya Jason ! Mine still looks like it did in those pics I sent you but I'm not backing out, just don't have the funds :p ! Yep, 2300 for a hi tork big block rebuild and about the same for the jimmy but, shoot, the jimmy's rare even around this page. TORK!! Did any of you guys ever ask Jim how much torque his 302 makes? with a small port head? Increditable! BTW Jason, how'd that air pump work for you?