Replacement of 1988 Crusader 220 (Chevy 305) with 1988 Chevy Silverado 305

Hello Guys,
I am in the process of replacing our port engine, 1988 Crusader 220 (Chevy 305-5L) and I have found in our vicinity completely rebuilt 1988 Chevy Silverado engine with throttle body injection TBI intake manifold, not for carburetor. The Silverado engine has new camshaft and crankshaft, balanced rod set, block was fluxed, cleaned and bored, it has new cam bushings and all new bearings, seals and freeze plugs. New high volume oil pump, new timing chain and gears,. Camshaft was torque ground for truck, head work done with new valves, springs, lifters. Engine was rebuilt a few years ago and placed in storage, but well oiled and preserved. It can be turned by hand for smooth rotation.
Assuming that the engine is good and functional the questions to you are:
1. Can the intake manifold from the old Crusader engine be used on this Silverado engine?
2. Would the raw water manifolds and risers fit on the engine block to the Silverado engine exhaust ports and bolt holes?
3. Would the engine mounts be the same?
4. Would the flywheel assembly from Crusader fit this engine?
Your kind replies are greatly appreciated.

chriscraftcat said:

new camshaft
high volume oil pump

1. Can the intake manifold from the old Crusader engine be used on this Silverado engine?
2. Would the raw water manifolds and risers fit on the engine block to the Silverado engine exhaust ports and bolt holes?
3. Would the engine mounts be the same?
4. Would the flywheel assembly from Crusader fit this engine?

Click to expand...

I bolded the 2 red flags that jumped out at me

would need to compare cam specs, but the typical performance cam people select for on road use, is often not good for marine.

high volume oil pump not recommended for marine use - marine engines can run for long periods of time at high rpm (over 3500), and that pump will empty the oil pan faster than it can run through drain holes back TO the pan...

another issue is pistons and compression ratio - some on road piston designs are not suited to marine use - Ricardo is the resource on piston selection - search up some of his posts on it.

1. Yes, if it has original heads
2. yes
3. the mounts? no, but the holes in the block for your marine mounts are the same
4. yes.

Ayuh,.... While I wouldn't put a Hi-flow oil pump in a boat motor,...
I wouldn't necessarily change that 1 either...
Pumpin' the base dry, usually don't happen til Way beyond the rpm levels We run in boats....

The Flywheel question can only be answered by knowin' what it's diameter is, 'n whether the block is drilled for that starter, for that flywheel diameter...
Some blocks are drilled for Both, Many are Not...

The SBC oil pump is nothing more than a rather crude rendition of a Positive Displacement Hydraulic Pump. In fact, that's what these are.... Positive Displacement.
One difference being that the SBC pressure relief is in the pump itself, whereas a hydraulic pump pressure relief is typically at the first spool valve in line.

The SBC pump is actually capable of 300-400 psi. Volume is a result of the gear size.

Now you must consider that the average and ideal SBC system pressure is approx 55 psi.
Any over-pressure or volume is dumped immediately back into the oil pan right at the pump body, since this is where the relief piston is.

Volume required will be a result of bearing clearances, how many bearing areas, cam follower and valve train lubrication requirements, and applied oil pressure.
If clearances are set up correctly, and if ideal pressure is approx 55 psi, then this predicates the engineers' pre-determined pressure/volume specs!
So then why the need for high volume?

One way or the other (with regard to our Marine cruiser engines)....., I don't think that the high volume pump is a deal breaker nor a engine saving atribute.


As to the flywheel question...
If both the previous boat engine and the proposed replacement engine are post 1987, then the rear crankshaft flange is the same.

Also, and if I recall correctly, some of the 5.0L flywheels provided a portion of crankshaft balancing.
I'd ask this question on a Chevy High Performanc forum.
Lots of them out there.


.

I'd get the block numbers from each and go see a local machine shop that knows what "marine engine" means. As noted above, 1987/1988 represents a design change (in GM's reference). Marine engines years and GM's are not always the same; ie you marine 88's may be GM 87's. The machine shop should have access to the data to answer these questions.

You're likely better off getting a rebuilt marine engine in the long run.

You'll also want to get brass freeze plugs if you use the 'burban engine