K10 downsizing from 454 to 305 roller

[Inman789]

on my 73 K10 (454, TH350 and NP203), I am removing my 454 and installing a 305 from a '88 Camaro. The 305 is a one piece rear seal, roller cam and full serpentine system. Ditching the TBI for a small electric choke 4 barrel (prob 500 cfm range). Have been researching what I can use from the 454 and what I will need to get. Can you help me determine if I have researched this correctly or not? Thanks

New torque converter - 305 to TH350 probably 2200 stall range

the 305 has a flex plate installed (had a 700R4) - will reuse this

starter from the 454 is new, dual mount kind so I will reuse that

will use the HEI from the 454 but will swap out the drive gear from the small cap that was on the 305

the 305 has a mechanical fuel pump block off plate, need to determine if the factory roller cam has fuel pump lobe and if so, will reuse the fuel pump from the 454 but will get a Howards Composite push rod 94475

The 305 has steel motor mounts on each side, I think they will work but I may need to get different rubber mounts with going from BBC to SBC? (have read a lot of conflicting info on that)

Will change out the SAE power steering supply hose fitting from the 454 and use that in the power steering pump that is on the 305 (will have a metric fitting) - that way I can use the existing power steering hoses

Will use a alternator adapter fitting to use the CS130 alternator on the 305 (CS130 to 10SI I believe it is)

One of my big questions is with headers. I am looking at Summit SUM-G9006 long tube headers for the 305 and it sounds like they will fit the K10. Any concerns with this being a K10 and not a C10 with header fitment?

I would assume it is standard practice to remove the front clip with engine swaps in a K10? I dont think my standard cherry picker would handle the height.

Am I missing anything do you think?

Thanks in advance

 

[nvrenuf]

The fuel pumps should be different.

 

[85K304SPD]

That is a nice looking 454. You must be changing it to get better gas mileage. I would bet that there is not a fuel pump lobe on the cam of the roller 305, so you will have to use an electric fuel pump. Find a spot to mount it that gets plenty of cool air, away from the exhaust. The motor mounts should work. Headers usually take some work to fit them in, espescially on the passenger side, but it can be done. Serpentine will be nice. I would try to keep the fuel injection on the 305. What are you going to do with the 454 set up?

 

[Inman789]

Thanks @nvrenuf and @85K304SPD. I will definitely look into the fuel pump situation.

I used the same serpentine system on my 406 in my Chevelle (1990 Camaro donor car) and love it. Havent decided what to do with the 454. Someone has put a cam in it and am looking for something much better on fuel for my daily driver truck.

So engine swaps, do most people remove the front clip?

 

[85K304SPD]

I have never removed a front clip to do an engine swap. It just seems like more work to me, but I have never done it. Id would be easier to get around without the front clip there, but its not that bad with it on there. There is lots of room for everything. Are you going to hook up the A/C?
If I was any where close, I would be interested in the 454. My sq body is not a daily driver, just for towing and fun, mostly.

 

[Shorty81]

It's easier with front clip removed. I never did myself, I aired down my front tires to lower front end. Removed good and had plenty of height with engine picker.

 

[nvrenuf]

Good luck with the swap. I had an '80 K10 with a 350, after swapping to a 454 I got better gas mileage.

 

[TotalyHucked]

Honestly if I were you, I'd look at getting a cam that's more for torque/fuel mileage and swapping that in there. I see your truck is 4x4, what's the whole setup (tire size, gear ratio, etc)? I'd put money on you getting worse or the same mileage with a 305. Less cubes/less power/has to work harder to move the truck.

 

[Inman789]

All good points @TotalyHucked, truck originally was a 350 engine, 350/NP203, obviously had some front end damage with a lot of 77 and newer body parts and I believe the 454 came from that donor. Worked hard on getting rid of the lift kit, stock suspension and stock tire size. Going back with all 73 looking pieces which has been problematic,... but back to the drive train.

The 454 may very well end up in my 71 Chevelle, so am pretty well convinced it is coming out and a SBC going back in. You are perfectly right though, the 305 may not be the best choice but that ship has already sailed

Digging into fuel pump options, I see that 87's had in tank pumps but where they all on the driver's side? (my single tank is passenger)

Thanks

 

[TotalyHucked]

Ahhh, fair enough. Yep, '87s had in-tank pumps and also baffled tanks (if you can call a little bread basket around the sender a baffle lol). Single tank '81-up trucks were driver's side, '73-80 single tank trucks were passenger. You could just buy the passenger side '87 sender if that's what you're wanting to do, they still offered dual tanks up to that point so both senders are available.

 

[Inman789]

Thanks. Looking for a "easy" plug & play "in tank" option for my 73 single passenger side that would include a pump and sender.
So are you saying that I may be able to source a 87 dual tank setup but only buy the passenger side? (and that would include a pump and sender) - sorry, I know nothing about the dual tank configurations.

 

[nvrenuf]

@Inman789 he's saying just by the '87 sender / pump set up for the passenger side tank and install it in yours.

You'll need to wire up the pump (preferably with a relay) and also get a fuel pressure regulator because the TBI pump puts out more pressure than a carb can handle.

 

[TotalyHucked]

Yep, what @nvrenuf said. All ya need is the pass side sending unit for an '87 truck:

Passenger Side Gas Tank Sending Unit - 3 Outlet with EFI - 87-89 Chevy GMC R/V Pickup

Reproduction fuel tank sending unit for 77-79 Ford F100, F150, F250 & F350. Correct for use on 4 wheel drive models equipped with a mid-mount plastic tank only. Designed to meet or exceed the performance of the original equipment they replace. Sending units are constructed from premium...

www.autometaldirect.com

Then you'll need a pump (an AC Delco EP381 is what my tuner usually uses, I've got a Walboro 255 for mine), to wire it in (with a relay like John said) and a fuel pressure regulator cuz these pumps put out too much pressure for a carb setup.

 

[Inman789]

wow, thanks. That is something to consider.

Still keep considering what you guys said earlier.....maybe doing work on the 454 and putting it back to a stock cam and idle may be the best option....

I could liquidate the SBC serpentine system for what I have in the 305...

A lot to think about, thanks everyone

 

[Vbb199]

Sell me the pesky, gas guzzling 454, I'll put it to good use