77crewcab said:
Okay I have decided not to do the TBI swap at this time but would like to look at getting a crate engine with a warranty for my burb. Of the two here which would you choose and why? I really like the warranty on the 250 HP engine but would it be enough power to move the burb? Stock was like 160 or something right so this would be a good improvement especially on a worn engine. Or would everyone go with the 290 HP just for the extra power. I plan to run a 77 q-jet with divorced or manual choke, Edelbrock performer intake, New HEI dist., Summit cheepy headers, and dual pipes with a H-pipe, and probably some Summit turbo mufflers. Would either of these accept the TBI in the future if I decide to do it? Which would you choose?
http://www.sdparts.com/product/10067353/196985GMVehicles350GMGoodwrenchCrateEngine.aspx
http://www.sdparts.com/product/12499529/290HP350LongBlockPreEmissionsGMCrateEngine.aspx
I've already been through this with my truck. I made the mistake of choosing the 290hp. VERY bad move on my part.
Here's what happened...they wouldn't warranty the 250hp motor in a post-1985 truck, unless I paid extra. For the same amount as the engine + warranty, I could get the 290hp motor with a warranty. I chose that. BAD idea.
Basically, they're the same, except the 290hp motor has a hotter cam. No other changes were made. The cam in that thing was originally used in Vettes from the 60's with more compression. This engine SUCKS in a truck. The solutions to this aren't ever good answers..."get a torque converter with a higher stall speed" or "put lower gears in your diffs".
I have no low-end torque, and my gas mileage with the new motor got cut in half, compared to the 18 year-old 305 with blown head gaskets it replaced. The 305 had every bit as much power in the driving range I used the truck for--daily driving.
You'll average about 15" of vacuum at best when at idle. Half of the gas will go out the tailpipe, unburned. What *will* be burning are the eyes and noses of anyone standing downwind of that thing.
This engine has cost me hundreds, if not thousands of dollars, both directly and indirectly. I've tried different carbs and playing with the timing. It's just barely adequate.
The only upside is that I learned a helluva lot more about engines after trying to figure out why this thing runs so poorly. So when I finally get to the engine, the first thing I'll be doing is recamming it. Although, I found a good running 250 straight six locally for $125. I may swap that in, and sell the 350 just to get rid of it.
Also...just a note. A friend of mine bought this same engine (without my prior knowledge) and dropped it in his '79 Firebird. He called me up recently, told me about it, and said, "it's weird...with the old motor I could spin the tires. With this one, I can't. I don't get it."
I didn't have the heart to tell him...
