My 318 2bbl '77 van dropped from 11.17 to 10.92 in the 1/8 mile by going from manifolds to headers. And the manifolds had dual exhaust. The more motor, the more the effect in my opinion.
ummm.... it takes nowhere near 450 hp to run high 12's in a A-body. My Duster runs high 12's with 3.23's, stock converter, and a real mild 360 (no lumpity lump lump..lol)
Tuning is key. One thing is when buying a set up like you did, you never know what or where the previous owner had things set. You might want to look at shot nozzle, accelerator cam. I run 750 double pumper on both my 360 small blocks. They even run a better 60 ft better with the DP than a...
It's not being hurt by the 750 if it's working correctly. You can try a different intake and smaller cam. Or, more converter and gears. Either way. I think 14.4 is a great baseline with a lot of opportunity.
Sounds like a drop in 361 with the 383 intake/carb. 15.60's in a B-body with 3.23's isn't all that dead if the rest of the engine was stock. The OP has his in a Duster, so I would assume lower 15's if he has similar gearing, and that's a far cry from the 18 seconds he says it feels like.
Where do you have the initial timing and total timing set ??
You verified the throttle is coming all the way open ?
what did each cylinder record on the compression test ?
What was the spark plug coloring ?
A "good running" 361 with a 4bbl and dual exhaust should be no slouch in a Duster. With a factory 2bbl and single exhaust they listed at 265 hp and 4bbl at 305 hp. I mean, it's not a 440 either. If it feels like 18 seconds, you are in slant six territory and I'd suggest giving the 361 a...
man, I remember when a 350 hp small block was rip'n, and a 450 hp big block was a deal (long before a ton of these aftermarket heads/etc came along). Now, it's 600-700 hp or stay home. And soon, a 1000 hp will be the standard and if you only want a wimpy 700 hp, then go cheap .... LOL. Fast...
I have a 440 for a future project. If you have good cast heads that flow 280 (paper work needed), valve springs good to .600 lift and ready to bolt on, for 450 bucks, let me know. I'll pay shipping.
...... But isn't the whole point of the 440 source ??? .... a way to replace the worn out factory cast for approx the same cost as rebuilding the factory cast... ???? with a 50 lbs lighter set of heads, and even in a mild case if you only gain 15 ft lbs of torque and 15 hp, it's still more of...
I do have sitting in a shed - - - a 440, a 318, another 318, a 360, so I can't say I'm a total 318 apostleship. And in vehicles, I have - - a 383, a 360, another 360, yet another 360, even yet another 360, a 318, another 318, a 196, and a 2.4.
Reading through this.... I'll take one for the team. IF you have new Stealth heads in the box, I'll go ahead and give you some free HP and drop your ET by trading you even up for my factory 452 heads on my 440. Even up! I'll take the loss.
Price has jumped about 200 bucks! Jegs has them
ProMaxx Performance 9440: 440 MAXX Aluminum Cylinder Heads Big Block Chrysler (B/RB) - JEGS High Performance
I'm not a huge buyer of aftermarket heads, but I disassembled my Speedmaster small block heads at home and inspected, found nothing, reassembled and no issues. It doesn't get driven a lot, but they've worked fine. So, some may be just fine OOTB
383 is a good engine. So is a 440. 383 takes its share of hits, but its a faster engine than a 340, and 340's are considered by many the cream of the small block crop !
Welcome! I love the '70 Coronets! One of my favorite Mopars !!! Love the front ends. You'll have to decide what you want from the car. My sister had a '70 4 door Coronet with a 318 and it was a tire fryer. A cheap 440/727 is never a bad thing... You'll have to decide your intended use :)
Ultra Black "maximum oil resistant" RTV for just about everything, and Ultra GRey RTV for freeze plugs, and T-stat housing is my general rule of thumb. I also like Indian Head Shellac for oil pan gaskets, valve covers, and sometimes timing covers