A mid-late 80's pick up cruiser. I have enough stuff to build a 340 or a 408. The truck would have air and be used for (some) daily driving, cruising and occasionally towing my 18' aluminum boat. Most likely I'll run a hydraulic flat tappet but may consider a hydraulic roller, nothing wild, just something that will make good power and not need a very loose converter. The truck would start with either a 904 or 727 and later maybe a 93 or so overdrive transmission. Gears would be either 3.21 or 3.55's. Initally I'll run a carb but would like to try fuel injection after everything is sorted out. Either engine will need new pistons as my Edelbrocks have been milled to 55cc. The 340 was 11.4-1 and the 408 was 10.8-1 with these heads and a Fel-Pro 1008. The heads flow in the mid 290's.

So, what would you guys build?

I have built and dynoed several 360, 410 low compression, small hydraulic cam engines for muscle cars and street rods, all made right at 400HP and idled with 16 inches or more of vacuum. Build the stroker. I would not waste a 340 block, I would use a lot cheaper 360, just me. I do a little hand porting to the heads, and usually some better valves.

hi
yep get a 360 ad a 4 " crank for a truck !

Cruise & tow RPM will help with cam selection, but a stroked 360 sounds best for that.
Did a 406" 360 for my 74 Duster. Cast crank & pistons, 340 rods, 9.5:1 CR, Thermoquad on Eddy Performer, iron 360 heads, pre-existing cheap headers, 8-qt pan & tray.
AT, AC car with 3.21s, 275/60R15s (28" tall), street car for city & highway.
Engle hyd FT with 214/224 @ .050 and .470/.504 lift, on 110 IIRC.
Great street manners, plenty of torque, ran strong & pulled 17 MPG @ 70-75.
That CR was pushing it with iron heads, aluminum would have been better.
Avoid the MP "stroker 360" pistons, they're actually for SBC rods.

Thanks guys.

The 408 ran 6.57 in the 1/8 in my 3240# 69 Dart so I'm looking to turn it down quiet a bit. The current pistons are Diamonds with a 20 cc dish and a .927" pin, so yes a GM size pin. The crank also has a GM size 2.10" journal, it opens up rod options a bunch.

Do what I am doing now , with a little less cam.
I am doing a 408 that will be around 10.5:1 with aluminum heads and a hydraulic flat tappet stick ............. 540 / 540 and 236 / 244 @ .050.
I plan on running A.C. but is going in an '80 Volare wagon that will be a grocery getter with occasional track blasts for the wife.
A cam with more attention toward the bottom end would be everything but economical for you.
But mileage isn't a huge concern for either of us I think.

No, mileage isn't a top priority. I'd prefer to keep it on 87 octane though.

What I should have said in my SBC rod remark was the pin end on the pistons was too narrow for a SBM rod; had to machine them wider.
I'm all for smaller diameter pins & etc.

If you are serious about overdrive and 3.21 to 3.55 rear gear, the cam choice better be real short duration. I would opt for a 3.91 rear gear , 408 cubes and O.D. that will allow a bit more cam as your cruise rpm in OD will rise to somewhere around 2000 or a bit more. A custom lockup converter will almost be a must.

I have 3.91s behind my 518. That is a very good combination. 3.55s or especially 3.23s would seem too steep to me. The only concern with 3.91s could be drive shaft speed. Joints, balance, and angles need to be dead on to cruise at hiway speed.

I tried 3:73, 3:91, 4:10 and 4:30 in my old pump gas Duster with the 518 C.I. low deck 400 stroker motor. That car ran the same ET and MPH, within .10 ET and .3 MPH, in both the 1/8 mile and 1/4 mile The car did spend less time in high gear with the lower 4:30 ratio in it than it did with the 3:73 and 3:91 in both the 1/8 mile and 1/4 mile
The higher ratio(4:10 and 4:30) would give it more starting line ratio than the other lower (3:73, 3:91) rear ratio would which in turn affected the stall speed in the converter, especially in low gear
Dave when you say 518 are you talking about the C.I. or trans type?

Id move to the G3 platform and use a junkyard unit with a carb. Holley adds to their engine swap section continuously these past few months with new swap parts, and have a dedicated section to 80s pickups.

There are a million G3s put there, no $ for machining if you get a good one.

540 Hemi, 518OD, 3.91s in 8 3/4.

Unlike the new engines, our old engines especially with some cam, need more RPM to be comfortable cruising. My '18 Hemi Ram will lope along on the hiway at 1,600RPM. But my 2nd gen Hemi really wants over 2,200RPM to cruise comfortably. So, I think it is very possible to get too low of a cruising RPM with our engines. Wedges might need a few less RPM and EFI could help. But there might be some trial and error to find out how low an RPM the combo would be comfortable cruising with.

You've got the heads, so my combo would be: 408, 518OD, 3.91s. The cam profile will be the big determinate on how the thing cruises.

Would you be able to run 87 with 10.8 comp ratio especially when in OD or when towing?

Its a given that the compression is going to be lowered. The whole idea of this build is to use as many parts that I have on hand that I can. Other wise it just sets on the shelf and is worth $0.20 on a dollar.