Brain Trust: Joe, Duke, et al on repl engines.

[Dennis C.]

A friend, on a limited budget, recently purchased a 1985 Corvette. The original engine is worn out. He is interested in replacing the long block with the "Universal, 350 CID 260Hp Goodwrench offering which has an approximate price of $1289. Noted in brochure is that will not "fit" 1986 & newer FI applications. When asked, Mr Goodwrench indicated this engine would not "work" in his '85. No reason why was forthcoming. They suggested he needed a higher horsepower engine for an additioal $1000. Could you please set the record straight on this issue. Inquiring minds have no clue. Thanks very much, Dennis

[Jim T.]

Re: Brain Trust: Joe, Duke, et al on repl engines.

I know of no reason this two piece rear seal engine will not replace the engine in your friends 85 Corvette. The 85 Corvette engine originally was a 4 bolt main 350 with forged pistons and will run on reg no lead gasoline, anyway mine does. The TPI intake from the 85 should bolt to the Goodwrench engine with no problems. The 85 Corvette engine was a 230HP engine, up from the 84's 205 HP.

[Duke W.]

Re: Brain Trust: Joe, Duke, et al on repl engines.

I'm not up to speed on all the details/interchangeability of the later Gen I SBs, so I can't confirm or dispute what Jim says, but I'm sure Joe can corrobotate.

Sometime in that era, the Corvette engine got aluminum heads and a roller cam, so maybe those are issues.

The TPI engines from that era had short duration cams matched to the long inlet runners and were designed for high low and mid-range torque with peak power about 4200, Even in Showroom Stock racing they shifted them at about 4000, so a "high horsepower" or high revving short block is certainly not necessary.

Duke

[Joe L.]

Re: Brain Trust: Joe, Duke, et al on repl engines.

Dennis-----

The engine to which you refer, GM #10067353, is a PERFECT choice for the 1985 Corvette application. Not only is it also approved by GM for that application (as well as many others, of course), but it's especially perfect for a Corvette application. That's because Corvette engines require many Corvette-specific peripheral parts. Often, these peripheral parts that are supplied as component parts of crate engines need to be removed and "discarded". However, the GM #10067353 is supplied with very few peripheral parts, so it's perfect. The Corvette peripheral parts are simply transferred to this engine. The engine doesn't even need to be painted---it's already painted black just like the original engine.

Everything from the original engine should bolt right up to this engine making for an easy assembly with few "surprises". I would recommend removing the valve covers and oil pan supplied with the GM #10067353 and replacing with the parts from the original engine. The 1985 Corvette valve covers were cast magnesium, perimeter bolt. The ones supplied with the 10067353 are plain stamped steel with perimeter bolts. Obviously, the original Corvette covers are going to be the best to retain and they'll bolt right on.

As far as the oil pan goes, the pan supplied with the 10067353 will work ok. However, the Corvette oil pan used for 1985 was a Corvette-specific piece and of lower profile than the one supplied with the new engine. To change it, though, one will have to change the oil pick-up and dipstick, too. The oil pick-up required will be GM #3830080 and the dipstick tube is GM #14084338. He could just transfer the dipstick, itself, from the old engine. I wouldn't recommend trying to reuse the oil pick-up or the dipstick tube, though. These are "nickel-and-dime" parts, anyway.

I would also recommend using a new waterpump with the new engine rather than transferring this piece from the old engine. It's just not worth transferring something like this since some of its life is already "used up" and it's MUCH easier to change it out for a new unit at engine replacement time. The pump he needs is GM #12522035, also known as Delco #251-500 (much cheaper through Delco). This is a NEW pump (that's what I'd use with a NEW engine). No waterpump is included with the 10067353 engine assembly (which is good because if one was supplied it would likely be a long leg style that wouldn't work for Corvette).

If he can "squeeze out" a few extra hundred dollars for the project, another engine alternative would be the GM #12499529. This engine, which is supplied in the same "trim" as the 10067353, is rated at 290 hp. So, for about $250 extra, he would get 30 extra hp. The choice is up to him, though; either engine will work perfectly.

[Dennis C.]

Incredible accurate insight. THANKS. DC *NM*

[Joe L.]

Addendum

Dennis-----

One other thing that I should have mentioned: while the GM #10067353 is approved by GM for installation in a 1985 Corvette, the GM #12499529 that I mentioned is NOT specifically approved for such an installation. The only significant difference between the 2 engines component-wise is the camshaft. The 12499529 uses the original Corvette L-46/L-82 camshaft. The vacuum or other characteristics of this camshaft might not be fully compatible with electronic fuel injection and computer control and that may be why the engine is not specifically recommended. However, I believe that many "L-98 Corvette guys" have installed camshafts considerably hotter than the L-46/L-82 cam with good results. Some computer chip changes may be necessary, though.

So, the long-and-the-short of it is that there may be some complications in using the 12499529 in a 1985 Corvette. On the other hand, there's an easy 30 hp to be gained for $250.

I do feel that the GM #10067353 will provide performance as good or better than the original 1985 Corvette engine. The GM #12499529 will provide better performance, but MAY require some other changes.

[Duke W.]

Re: Addendum

Joe - what cam is used in the 10067353 long block, and assuming it's not a cam used in earlier carbureted engines (i.e. one that I am familiar with), do you know its basic specs.

Duke

[Joe L.]

Re: Addendum

Duke-----

It's a camshaft very similar to the old '929' cam. It has intake lift of 0.390" and exhaust lift of .410" (with 1.5:1 rockers). Intake and exhaust duration @ 0.050" lift are 195 degrees and 202 degrees, respectively. All of these specs are identical to the '929'. However, I believe that there are some other specs that are different. I think that the part number is GM #14088839. This cam is also the current SERVICE replacement for the '929'.

[Duke W.]

Re: Addendum

Yes, that sure sounds like the 929. Could be they tweaked the the lobe dynamics a bit, and maybe the separation angle. I doubt if there would be much difference in measured output with either cam.

The combination of this valve timing and the TPI system makes for a real "torque monster" SB!

Duke

[Joe L.]

Re: Addendum

Duke----

GM has made several, successive slight changes to the '929' cam as evidenced by at least 2 supercessive part numbers. I believe that each of the changes was related to emissions-related issues.