Do if change my L69 305ho for a LO5 350 (stock except for a XE268 cam) worth the swap.The 350 is free $ just need to replace the cam & some gasket
My old 355 flat top piston with the XE268 cam did 14.01-99mph the cr was 9.73 not 8.75 or 9.3 as the LO5 and it was with the th700

 

Free is free but I would rather instal an LT? before either of those, L69 is better though.

 

Here are the specs for the 3 L05 350 truck engines. Roller compatibility is hit and miss. To tell, pull the intake and look in the lifter valley. You will have 4 possibilities. No roller boses, untapped roller boses, tapped roller boses, or a roller cam.

Some specs I found published and others (such as cam specs) were measured in stock engines.

A.) Was used in 1/2 ton trucks, vans, and suburbans under 8,600 lbs GVW.
It had 9.3:1 compression ratio, 193 head castings(1.94/1.50 valves 64 cc chambers), a cam that measures 248/252* @ .008, .382/.401 lift, 109* lobe seperation, installed on a 112* intake centerline. The stock TBI is 400 cfm @ 1.5 in/hg and they typically have a better flowing intake than L03 cars do. There are 4 different casting numbers on the intake that I know of. These typically use 61 lb/hr injectors with 68 lb/hr units showing up ocassionally. The air cleaner and exhaust vary between lines, but they are typically much better than a stock L03. For 1987-1994 these are rated 210 FWHP @ 4,000 and 300 ft/lbs @ 2,800. For 1995 it is rated 200 FWHP @ 4,000 and 310 ft/lbs @ 2,800. Strangely, there were no mechanical differences, just programing.

B.) Was used in 3/4 and 1 ton trucks, vans, suburbans over 8,600 lbs GVW. It had 8.75:1 compression, dished pistons, 191/810 head castings (1.94/1.50 valves 76 cc chambers, typically a L03 peanut roller cam (could also be the old "929" cam as well depending on the year/application) The L03s roller specs at 244/258 @ .008, .350/.385" lift, 109* lobe seperation angle, installed at a 110* intake centerline. The "929" specs at 260/271 @ .008, .390/.410, 112* lobe center, installed at a 108* intake centerline. It shares the same TBI, 68 lb/hr injectors, and typically the highest flowing intake. The exhaust is typically shared with the lighter duty L05. For all years the engine was rated 180 FWHP @ 3,800 and 300 ft/lbs @ 2,400. Note that some of these engines have forged cranks and beefy rods. All have sodium filled valves.

C.) The third L05 was in a class of its own. It was used in the C60 series of medium duty trucks. It is a completely different animal than the lighter duty engines. It is also 8.75:1, forged crankshaft, forged beefy rods, dished hyper pistons, 810 head castings (1.94/1.50 valves(sodium filled exhaust), 76 cc chambers, and water cooling of the exhaust valve guides. The intake is typically the best appearing unit. The TBI contains a weird looking governor unit and a totally different pod than a car/light truck TBI. The injectors in this unit flow around 70 lb/hr at 12 psi. The TBI injector pod is fitted with an AFPR with an adjuster screw right up top in the open. The TBI flows closer to 550 CFM @ 1.5 in/hg in stock form. The exhaust is odd in itself. The catalytic converter is placed rear of the muffler, shortly before the exhaust exits the truck. The engine uses a roller cam almost exclusively with the following specs (I haven't measured it installed in an engine with a degree wheel and indicator, but GM list it as 196/206* @ .050, .431/.451 lift/ 109* lobe seperation installed at a 112* intake centerline. The engine is factory rated at 215 FWHP @ 3,800(its TOP goverened RPM it makes more at higher RPMs but is restricted in a heavy truck by the governor) and 325 ft/lbs @ 2,600. With an edelbrock 3704 intake bored to 2", open center 454 style TBI spacer, 75 lb/hr worth of injector, 1.6:1 roller rockers, JBA shorty headers, electric fans, an underdrive crank pulley, and DIY prom tuning, it has pushed out over 248 RWHP @ 4,800 and 317 ft/lbs @ 2,700. It has pulled a 5,300 lbs G-Van with 3.73 gears, a 700r4 with a 2,000 stall, and P295/50/R17s to the following times

 

Put the L69 heads on the LO5 block with new cam.

 

the L69 should have 416’s on it, that will bump compression to around 10:1 on that LO5. Depending on the year the LO5 block will most likely have roller lifter provisions, and I’d consider running a roller cam, use used roller hardware if you have to keep it cheap.

Either way, that with something like a xe268 or xe268hr, a modern design, high rise dual plain intake (performer EPS, the new wieand design…), headers, decent exhaust… should make around 400hp or more and get you at least deep in the 12’s, faster with a really well matched combination.

 

The L-69 is a H.O. 305 and has more hp than the LO-5 it has more compression a better cam and i think they have a better cyl head.

 

I don't know where you figure that the L-69 has more HP than the L05. The highest the L69 was rated was 190 HP. The L05 was 190-215 HP depending on the application and the year model. The L05 also makes like 60 ft/lbs of torque more than the 305 HO did.