There are a number of interesting assumptions in this thread...
An LT1 cannot be converted to an L98.
"Tuned Port Injection" like "Generation 2 Small Block V8" were marketing terms. "Tuned Port" was a name coined by Chevrolet marketing weenies back in the early 80s for the port fuel injection system used from 85-91 on the Corvette and until 92 on the Camaro and the Pontiac Firebird. It gets its name from its long intake runners, the lengths of which were selected or "tuned" to cause an increase in low-speed torque.
The "Tuned" name was dropped in 92 in favor of another, even less descriptive moniker "Multi", but the 92 LT1 (along with the later L99 and LT4), also, used intake port length tuning to affect torque...but the port length was much shorter, which raised the rpm for which the runner length was "tuned". This also allowed the LT1 its higher rpm range and greater power.
The Generation 2 (or "Gen 2") Small-Block V8 arrived in 1992 in Corvette and in 1993 in Camaro, Firebird and the GM B-car. While its block architecture was very much the same as the traditional small block (the so-called Gen 1 of 55-91), there was a big change in the cylinder head and cooling system to acomplish the "reverse flow" cooling discussed above.
"Nelson84" is incorrect in saying the L98 (350 cuin version) of the Tuned Port engines are "easier to mod". Reality is each engine has good points and bad points as far as their potential for modification, but, if "modification" means significant increases in horsepower and an extension of the engine's rpm range, the L98s big problem is the tuned port system itself. The intake manifold, the runners and the plenum are highly restrictive and a big problem when modification for high horsepower and high rpm are the goal.
"Nelson84" makes the misleading statment that the L98 makes "more torque". It is true that, in stock trim, the L98 engine has slightly more torque output between off-idle and the mid-range rpms but, if you consider the entire useable torque curve of the engine and the torque peak, the LT1 makes "more torque".
As for "no Optispark" well....yeah, the L98 had the rear-mounted distributor, but that "no Optispark" is an advantage, I think, is debateable to a certain extent. I'll admit that the early ABITS distributors where flawed by poor moisture sealing but that flaw was eventually eliminated. The later ABITS distributors were not the reliability/durability problems the first ones were and were a much more accurate way to control ignition.
No doubt, TPI systems look better under the hood. The long runners are pretty darn sexy.
Another comment above that Tuned Port means one injector per cylinder is not correct. The LT5 has two injectors per cyinder. "Tuned Port" refers to the length of the intake runner not the number of injectors per port.
Yet another comment above, the one about being able to backdate a Gen II with a Gen I distributor by changing the intake manifold, is not correct.
Someone asked about the Vortec 350 truck engine. GM called that "Gen IE" and they were basically the Gen I engine with the best of the Gen II cylinder head, but no reverse flow cooling.
Lastly, the final interation of the Gen II, the 330hp SAE net, LT4 was the most powerful production Small-Block V8 which used the traditional block design. If the old gross power rating system used in the muscle car era had still been valid, that engine would have been rated at about 410-430 hp. Such a power level would have been impossible using the L98 style induction and 2-bolt main cylinder block.
