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You've got a lot of techncial problems that will really push your level of skill and knowledge.
To start with the 88 Caprice came with a fuel injected computer controlled 305 V8 and 4 speed overdrive automatic designated 700R4 or 4L60 with computer controlled torque converter lock up.
The Caprice engine uses a one piece rear main seal, this includes a different configuration on the rear of the crank that will not mount to a TH350 flexplate. 350 SBCs are internally balanced so the flywheel or flexplate is neutral balanced so you at least don't have the 400's balance problems to deal with in parts selection.
You may have starter gear problems and starter mounting problems between the 73 block and the TH350 the later using a 168 tooth ring gear but the 73 block might only accept the 153 tooth starter. Most but not all blocks are drilled for both after 69. So you need to check this out.
Your 305 distributor is all computer controlled, it won't work in the 73 engine without the 88's computer in the loop to compute timing. that of course means all the engine and transmission sensors need to be there. Since you're eliminating the fuel injection, you might as well convert to a HEI distributor from 76 to 86 model years. These trigger electronically but retain vacuum and mechanical advance and don't require a computer. They also just use a simple 12 volt power connection. If you used a point distributor you have to run a switched source of 12 and 9 volts. 12 is used during cranking but is hard on point life so the ignition switch reroutes power through a resistive wire when in the "run" position supplying 9 volts which is a lot easier on the points. So you'll probably have to fit an older start switch to the steering column to accommodate that need if you go with points.
The 88's accessories are designed to be mounted on cast brackets that align them for the serpentine belt drive system. The bracketry does not permit installation of a V-belt arraingement that was used on the 73 engine. The 73's original castings will accept the cast aluminum brackets from the 88 allowing it to be converted to serpentine belts, but you must also use the 88's reverse turning water pump and fan. Or the front of the engine can be back dated to use the 73's accessories with V-belts, this requires the use of the 73's water pump and fan.
The car's speedometer is electronic and is controlled by inputs from the computer which is sourceing information from an electronic sender in the transmission. There is no such thing in a TH350. This means either the tailshaft of the TH350 has to be modified to accept a mechanical to electronic resolver or the speedometer has to be replaced with an aftermarket mechanical model. The latter is the much less expensive solution.
You also have a crossmember mounting and driveshaft length problem because the 700R4/4L60 transmission is about 4 inches longer than a TH350. So the crossmember has to be modified to move the rear mount foreward 4 inches and the driveshaft has to be lengthened 4 inches.
Overall both performance and economy will be substantially reduced with your combination because the 700R4/4L60 runs almost a full ratio lower gear in first, so without adding more rear axle ratio and a lot more power, out of the hole acceleration will be markedly reduced. At the other end of operating this thing; with a more highly stressed engine and stiffer rear gears without the 4 speeds overdrive at cruise to high speed driving the fuel consumption will be drastically increased maybe as much a only getting half the mileage it did with fuel injection and the 4 speed transmission.
You'll have to fix the excess fuel pressure from the FI pump in the tank. This will require multiple regulators, or return the system to a design that will use the engine driven pump of the 73. However, this will prove to be one of the simpler problems.
In my experience this transplant sounds like a lot of screwing around and a lot of money lost with no gain of anything. If you want to make a runner out of this thing, the direct path is a 350 with Vortec heads. Get a TBI to Vortec intake from GMPP or Edlebrock. Use your existing sensors. Put in a cam of about 210 degrees measured from .050 " lift, with about .45 inch lift. A set of 1.6 rockers. 1 and 5/8s dia headers, come off the collectors with either 2 and 1/2 pipes for duals, or go single with a 3 inch pipe and matching cat converter and mufflers. Have Turbo City bore out your TBI for 2 inche throttles and Fastchip blow a PROM for all this and stand back.
Your mom's boy friend is right in thinking this project has problems, going the way you've laid out this has problems you don't even know about yet, the solution to which will be big bucks and lots of time. so if you think the 73 engine will save money and make lot of power, think again.
I'm not even into the heads of the 73 engine which are just totally obsolete by any modern standard. There's nothing you can do with them short of trashing 'em and starting over. Modern fast burn chambers and port shape technology have left anything made prior to the mid 1990s so far behind it's pitifull. Vortecs and heads that share it's "fast burn" design concepts (factory or aftermatket) bolted on to any pre 96 (92 for Corvettes and Z-28s engines) out-of-the-box will beat the best ported old time "power pack" type heads by an easy 40 horses. What they do to the old Smoggers of the 70s and 80s, like your 73 heads, is just shameful, they'll blow them away by 60 to 80 ponies. All this by just bolting them on, doing nothing more to the engine than taking the old heads off and putting the Vortecs on. However, you could make use of the 73 block if it's any good. This with a modern rebuild and flat top or "D" dish pistons could make a decent, but typically oil leaky, bottom end for a more modern engine. Otherwise this generation and half old technology is far beyond obsolete.
Bogie
Edited 7/15/2006 4:39 pm by oldBogie
Edited 7/15/2006 4:47 pm by oldBogie
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