Redbeast, I didn't do much at all to the frame. Maybe because the truck is the short wheelbase model, it doesn't seem to flex all that much compared to most anything else I've built up. However, I did two things; one was to remove the rubber insualtors between the body parts, cab/bed, and put in aluminum spacers. This makes the cab and bed a load path which has the effect of stiffening the entire vehicle. But it's mighty noisy inside as a result. The second thing was to cut a section from the left side of transmission mount cross member and weld into it the exhaust hump section from the right side of a junk yard cross member to provide left side clearance for the dual exhaust. However, I'm sure this doesn't improve frame stiffness. I left the fuel tank in its original position which results in having to leave the left side angle in the cross member which I think is what reduces the truck's resistance to side impact. Something its well known for, you don't want to get "T" boned in an S-10/15. The other problem was getting left side exhaust pipe clearance around the fuel tank. The pipe jogs between the tank and the drive shaft, it's mighty tight. I insulated the pipe through this section to keep it from cooking the gas tank. Upon reflection, if I was to do this over, I think I'd move the tank to where the spare tire is and just not carry a spare, I don't anyway because the mufflers are back there. Many years ago I put a Mustang 289 into a Ford Courier (Mazda PU by anyother name) and mounted the stang's fuel tank in back where the spare once was, this worked out pretty well. When going out of town, I just threw the spare in the bed and bolted it down. It isn't like I can't do that with the S-15.

Bogie

I have a 350 myself I'm wanting to rebuild and I found teh book How To Build Big-Inch Chevy Small Blocks by Ed Staffle a HUGE help.  Somewhere in teh book it says that anyhting more than 1hp per cubic inch is a HUGE undertaking but the book outlines 6 or 7 engine builds that are "low budget" with a punch.  Good Luck

Frank

I haven't looked under my S-10 a whole lot since it's just a daily driver, but if the pipes going to that 'tight space' near the tank are just to get the exhaust to the back of the truck, why not just weld or exhaust strap some short straight pipes behind the muffs with a downturn and point them outward just behind the rear wheels ? I did that on my '77 K-5, -  I know, a lot bigger and loads of room to play with under there, with but I figured it was just more pipe with bends and therefore more exhaust restriction, so I cut them off and installed a 1-foot section with a 45-degree down turn on each side, and pointed them behind the rear wheels so the exhaust doesn't heat up my rear tires.

I had problems with gas fumes when I had the muffs with no pipes, but the short section of pipe did the trick. First I bought an auto-parts pipe- bent section that looked like a turkey neck and that really brought the exhaust diameter down from the 2-1/2-inch  pipes. It sounded "like crap" - as 'fat bastard' would say.., even with the twin flowmaster super-40's on it. I quickly replaced them with two short mandrel bent pieces of the same length, and turns I got from Summit Racing. It made a big difference, and everything is right with the world now!

There's a name for a spare tire in the back of a truck ya know - It's called a 'redneck back seat'. I ripped out the rear bench seat out of my K5 beast, and the dog's staked a claim to it as his bed now. He can keep it for all I care. It's just dead weight in the truck as far as I'm concerned - just like the 60+ lbs of dead weight in A/C system parts, compressor, and all that related junk I ripped out under the hood. I can bring two mexicans accross the border now with all the room I have in there! - If I would ever wish to do such a hare-brained thing!

If you can't find a better place to keep the spare tire on your truck just throw an old t-shirt over it, and duct-tape a "git-r-done" ball-cap on it, put it in the passenger seat and secure it with the seat belt. Great for driving in the car-pool lanes in California & Florida! The highway pigs won't be hasslin ya during rush hour! - just an idea.

In keeping with the theory that the hairdresser has the worst hair-do in town, the pastry chef lives on Ding Dongs, and the mechanic has the crummiest truck in town, I short cut the exhaust system on my S-15 when I built it. Originally it used a "Y" pipe to the right side. That connected into a 3 inch pipe which connected to a 3 inch universal catalytic converter which then used more 3 inch tube to connect to a Walker muffler. Then another piece of 3 inch ran out and dumped ahead of the right rear tire. Get the feeling I've got a lot of 3 inch tail pipe tube don't ya.

Anyway, the whole system was too flexible and it worked away at the junction of the "Y" pipe causing fatigue fractures in the metal. I welded them up a few times, each time telling myself I'd replace the whole system, which I always put off to some future date. Finally the fractures got so bad I couldn’t ignore it because the constant welding on welds built up a stiff spot that kept breaking more and more often at the weld edges. So I got to work on what was originally planned, which was to bring duals all the way back to the rear and pass the pipes thru a hole on each side of the valance panel that replaces the rear bumper. I wanted to move the mufflers to where the spare tire, I don't carry around, mounted to move a bit more weight bias behind the rear tires as traction, or rather lack there-of, is a problem.

Since this thing is intended to be a "SLEEPER", there isn't much on the outside to give it away. But I thought the duals out the back would provide a little indication that there's a bit more than meets the eye in the thing and give the truck a cleaner look. To the casual observer that rolls up on it now the only giveaway that’s there’s more than meets the eye going on with it is the 95 Z-28 wheels and tires. However, if you walk around it and know what you're looking at it starts to give up its secrets as you see rear disk brakes through the wheel spokes, slapper bars hanging on the springs, a big fat rear anti-sway bar, and if you get that close you'll see the girdle rear cover on the diff. Peering in the cab you'll see a set of Autometers where the original instrument panel was and a flashing red light from the paging alarm system. Yes there's been several theft attempts, one of which did a lot of damage to the driver’s door when the thieves tried to twist out the door lock. There's a B&M Mega shifter on the floor with a bunch of switches that allow control of the transmission's line pressure and provide an override of the computer for full control of manual shifting and converter lock-up. Under the tach are 5 LEDs that tell you which forward gear the transmission is in and whether the converter lock up is under manual or computer control. Other than that it's just an old gray S-15.

Bogie

Cool !!  You didn't mention the cats, or lack thereof. I'm not sure how strict the 'leash laws' are in your area, but I've heard of folks who hollow out the cats in case anyone wants to take a peek under the car or truck so that the cats "are there". The best way to handle this if you got vehicle emissions inspections is to install the cats with high quality exhaust straps ( from Summit Racing for example ) and swap out your hollow cats for the real ones just to go take the emissions test and then 'unleash the big dog when you get back home. Swapping out the carb with a street legal one temporarily is also a good idea. - Never throw out that old 600 cfm Holley carb!

I also messed with Flowtech Warlocks for a time - removable 3-inch pipe caps that give you temporary straight pipes, as well as the ringing ears & choking exhaust fumes that go along with that mod - I would always get thumbs up from all the kids around the neighborhood when I would drive by 'sans le caps' . I know 'the law' has problems with this arrangement in most off-track sitiations. It got to be more of a pain than it was worth, so I replaced them with Flowmaster Super40's - I love the DEEP growl they produce. They put a lot more hair on my chest the first time I floored 'em! They also produced a sh$t-eating grin on my face the remains of that day.

It's a '77 truck so I don't have to worry about cats, it never had any. The one thing I didn't like is how it changed the exhaust note to a somewhat milder sound when I installed the H-pipe on my exhaust. I noticed improved power and response, so there's no way I'm pulling the H-pipe out now. True dual with no cats is the only way to fly in my book.

I had a buddy a while back with a 426 in an old '80's Monte Carlo. It was a real sleeper in every detail. It was primer gray, scuffed up, dents here & there (for effect) with low end BFG tires on it. he even kept it muddy to add to the look. He rigged a section of exhaust pipe behind the headers, that he could 'drop out' from inside the car with a lever when he got ready for business. He also had a big Nos bottle in the trunk with the valve in the center glove compartment. He blew away a lot of unsuspecting slack-jawed folks in "the snoozer" as he called it.

redbeast im glad you said what you said because i ran into the same problem with my z71 a while back at a chevy dealer.they tried to burn me for $500+ dollars for an 30$ part so i second that as far as tryin to do things yourself ,if possible!!!

I live in Seattle, we must submit to and pass a sniff test for OBD I and older systems every other year in order to keep the vehicle licensed for the street. Newer vehicles with OBD II are just plugged in and data unloaded from the onboard computer as to system function, and they tell on you if you've been messing with them. OBD I systems don't tell about modifications to them, so if your exhaust is within limits, that's as far as the check goes. So while it's technically illegal to mess with the system as installed by the manufacturer, if you can take an L-98 and pass with a Holley 4 barrel instead of the original injection, you're good to go.

Washington state as far as I can tell has no official way to deal with modern rods, unlike California.  Down I-5 they, working with SEMA, came up with a scheme that allows hot rodders to modify vehicles and get legal approval. Basically Calif. says that if you put a modern engine like a LS-1 into an older vehicle, it must SMOG to the requirements in force for the year of the engine. So this means you have to find a way to accommodate all the stuff right down to the "Check Engine" light that made the "total" installtion certifyable. That can take some creative engineering when stuffing an LS-1 into a 57 Belaire. So the state of California provides through the office of Automotive Repair what's called a "referee". You submit your completed hot rod to a referee for inspection, they look it all over and agree, or not, that your installation includes all the functionality required of the LS-1 as certified by the California Air Resources Board (CARB). If the ref agrees that your configuration works as originally intended, your vehicle is given a plastic sticker that goes on the inside door panel, like a manufacturer's ID tag, stating the changes that were made and techncial acceptance by the State. This is free to you except for your time, and belive me you can expect to spend all day on a simple installtion and maybe more on really complicated mods, so this is a fair sized investment of taxpayer money on your behalf. At that point you can go to a SMOG station and have it checked for emissions, if it passes and since the ref also checked it, there's no reason why it won't pass, you get your annual registration. What all this does is that Calif. law allows an exemption for cars that don't SMOG as they age which states that if it's stock and you spend $200 for work at a certified emisssions repair station and it still won't SMOG, you're issued an exemption. Since the State agreed that your Hot Rod meets it's standards, if it ever fails to pass SMOG, you're entitled to the same respect as if it were stock.

Washington state holds to Calif standards but has no process to "legalize" hot rod configurations, so if and when your LS1 powered 57 fails emissions, or my LT 4 powered S-15, it appears your in no-man's land where you've either got to bring it into acceptable limits or park it.

Bogie