Earlier this week we mentioned that we brought a few new projects into the garage, and this is one of them: a beautiful 1995 Yukon GT — the two door version — that spent its easy 24,000 mile life in Arizona.
As clean and nice as the Yukon might be, though, it’s horribly underpowered. With the stock 5.7L (350 CID) engine producing only just shy of 200 HP, this SUV makes a lot of racket but doesn’t really do much to move itself. The question we’ve been pondering is how to give this creampuff a much-needed injection of power without sacrificing driveability or reliability.
In our minds, one of the big factors in driveability is fuel injection. We don’t want to give up the Yukon’s instant start capability, and we don’t want to be crawling back under the hood every time the weather changes, either. So high on our list is keeping the injection. Calls to numerous crate motor manufacturers made it clear that dropping in an injected crate motor would be very, very difficult. Most of the pre-configured injection systems available are designed more for installation in older, carb’d engines as opposed to integrating with other modern systems like an electronically-controlled transmission and computer controlled gauge package. In short, we were told that to install an injected crate motor we could expect to scrap the transmission and build our own gauge package for the dash. And we could forget the climate control. Ouch!
Enter GM Performance and their very thorough catalog. It was a bit difficult to track down these guys. Calls to GM directly were answered by people who’d either never heard of the performance division or forwarded us to someone else they thought might know something. Eventually one of them did, and we were informed that GM Performance parts are only sold through dealers which support the program. Currently there are five of them in the US. Luckily, one of them is located relatively near our offices and shop here in Texas, so we made a beeline there.
Our particular dealer was quite friendly as they’d only recently joined the performance program and hadn’t yet made many performance parts sales. They had designated one of their parts staff as the performance contact, and he was very helpful once we explained our situation.
GM Performance offers a number of engines that are somewhat “bolt-in” for our application, including a bored-and-stroked 383 and a “high-output 350.” The 383 was a bit much for our needs, but the H.O. 350 sounded great with an estimated 330 HP. We brought the Yukon in, and the specialist went over it with us, reviewing the parts in detail. We did discover that the Vortec-style manifold included with the H.O. 350 wouldn’t match our non-vortec injection, but luckily the H.O. 350 also comes in a long block format sans-manifold, injection, or carburation. Combining this package with a special GM Performance manifold that matches both the new engine and old injection made the perfect package for us, allowing us to keep the stock injection, computer, and all associated components.
It does appear that this won’t be entirely a straight “bolt-in,” but it’s about as close as we’ve been able to find. Just from what we can see right now, we’ll need to re-route the large vacuum line to the brake booster — it’s on the opposite side of the new manifold — and we’ll need to fabricate a new alternator bracket. There’ll likely be other issues, but none of them seem to major at this point. Obviously we’ll have a lot more to say about it once we’re under the hood with it.
We placed our order and were happy to discover that our dealer stocked the H.O. 350 long block. We did have to wait for the manifold as it needed to be ordered, but it arrived just four days later. We also picked up an intake manifold gasket kit as the new and old engine both use a formed gasket that should come from the factory.
The engine itself is beautiful. It’s easily the cleanest engine we’ve ever had in the shop. There’s a sticker on it indicating that it contains no refurbished parts whatsoever; It’s entirely new manufactured engine. Wow.
In preparation for the swap, we also tracked down and ordered a factory manual for the Yukon. If you’ve never used a true factory manual, you’ll want to give them a shot. The Chiltons and Hanes manuals can be helpful, but they contain nowhere near the detail. For example, the manual for our Yukon — a manual shared with the rest of the ’95 C/K truck series — weighed 19.5 lbs and comprised a 5″ thick looseleaf notebook as well as two perfect-bound books covering unit body repair and driveability/electrical systems and a couple of tape-bound supplements and diagrams. That’s a thorough manual.
Some dealers make finding a manual a bit difficult, but that’s not really the case with GM. If you ask at most GM dealer parts departments, they’ll give you a toll-free number to call which connects you directly to Helm, Inc. Helm prints the manuals and sells them directly to the public. They’re not extremely cheap. Ours ran just over $150 for the set, and around $195 with two-day shipping. (Have we mentioned that we’re not that patient when we have a cool project to jump into?) On the other hand, if you’re going to own your vehicle for any serious time — or you intend to make major modification like the engine swap we’re undertaking — the factory manuals are well worth the money.
Our manual arrived 5 days later, despite our shipping requests. When we called to check on it, Helm wasn’t very helpful. At first they indicated that all shipping took a minimum of six days, regardless of what form of shipping we’d paid for or what assurances our salesperson had given us regarding ship date. Then they said that they wait four business days to ship regardless of method. After lots of wailing and gnashing of teeth, a supervisor admitted that the manual had indeed been shipped the day after our order as agreed, and reluctantly provided a tracking number. UPS added a day to delivery (bringing it to three days) and bumping it onto a weekend. Hence our 5-day delivery.
Next we’ll begin the slow tear-down proceedure, and we’ll drop you another update to let you know how it’s going. And if you’re considering doing something like this yourself, drop us a line. We learned quite a bit during our initial work and we’re happy to pass it on to you.