Hey all. So, I have my 85 SS. It's a no-budget car at this point...but I'm not letting it go. Money's tight, bills are rough...and I have 4 kids...but I'm hoping to have my car running either this summer, or next year.

I'll just give you some info. The engine is actually a freshly rebuilt MERCRUISER 260, bored .30 over, and from what I understand, that would make it a 355??

I inherited the freshly rebuilt engine from my father, as his boat project stalled.

Other than a .30 over Mercruiser 260, I added an Edelbrock RPM intake, and a Comp 286h Camshaft. I have a used th400 tranny, and 3.73 POSI rear end. My carb. is a Quadrajet, but I'm still not sure exactly what it is...it came with the car (the original engine that came with the car was a 350). I added the POSI to the rear-end.

My car has previously been stripped of all heat and a/c components, though I wish I could have all of that! I'm on a budget, and at this point, I literally need: a new radiator, headers, torque converter (to match my cam), and a battery...to get this car running again.

My cam calls for a 2800+ stall, but jegs said I should be ok with something 2400. At this point, I'm just trying to get her back on the road, and from what I've read...I have some good stuff to work with. Now, other than the obvious (relating to the marine engine- freeze plugs, etc.), any thoughts on my set-up?? I will get some cheap roller rockers if I can but at this point would like to put her back together. I'd just like some input, and especially if anyone has had a simillar setup...how can I expect it to perform.

It's going to be a toy. My work commute is 2 miles, and I'd like to take cruise on weekends, and take it to the track once in a while. Any thoughts??

 

Also, my tranny came out of an older 70's motor home. I'm confused as to whether a shift kit would help...being that it should already be suited for hard shifts?? Again, any thoughts??

 

a shift kit would help. the 400s arent known for having hard shifts even with them though. theyre also a bit on the heavy side.

on the cars performance its all going to depend on what heads are on this thing and what kind of compression it makes. without knowing that its pretty difficult to say. if its a low compression motor with small valve heads it could make 250hp if its got some compression to it and nice heads it can make 370hp. i dont see it making more than that with the cam you have.

i looked up your cam specs. i run a cam thats quite a bit more radical than that on 2500 stall so you should be ok(my motor also has quite a few cubes on yours though). i think that your cam has a good amount of duration but is a little low on lift. i wouldnt go with 2800 stall just because it forces you to really get into the gas to get the car going at lights. im also curious to see if your car is going to pull enough vacuum to properly run the power brakes. i wound up putting a vacuum reservoir in mine.

 

Thanks for the reply! Unfortunately, my freshly rebuilt motor has brand new 'stock' heads, and .30 over stock pistons. I'm not sure what 'kind' of heads they are...they're nothing fancy though, just new.

I'll take your advice on the shift kit. It just confuses me because most kits in my budget have a towing/rv stage, and a strip stage. Being that the trans came out of an rv, I figured the 'rv stage' is already there. BUT...that's just me assuming. I'll get a cheap kit, and hope for the best, being that I can't afford to have the trans rebuilt yet.

I did some more reading on the 'differences' between a mercruiser 260, and a chevy 350...and supposably a stock mercruiser puts out 260 hp, hence the title '260'. If that's the case, I was kind of hoping that the intake and cam would have to do it justice...

I'm also going to take the advice on the converter. I'm going to go with a 2400 stall. And yeah, the vacuum question is an issue for me too...but I've had a few people suggest that I'll be fine...and Jegs recommended that particular cam...so, I'm crossing my fingers.

Thanks again for the input.

 

You should be fine..

 

if you pull the valve covers off you can look up the casting numbers on the heads. thatll let you know what youre dealing with. itll give you an idea of compression ratio, since youll know what cc the heads are, valve size, and what they flow. the big problem with gen 1 small blocks were the heads. there really werent many performance factory small block heads. a lot of people recommend the double hump or camel humps or whatever you want to call them, but they really werent anything special other than having the 2.02valves. they have pressed in studs and i dont believe you can run guide plates with them. they need to be machined for the screw in studs and guide plates and i believe many of them arent drilled for accessories. they kind of defeat the purpose of being a budget performance head since they require machine work. the best factory option would be the vortec heads. they can be found at almost any junkyard, but they require a special intake manifold and i believe are also pressed in studs. best bang for the buck in iron aftermarket heads would be the iron eagles or the sportsman 2s. heads are key to making power and choosing a cam without knowing what heads you have is difficult. did you change valve springs as well? i was running a milder cam then yours with my original small valve factory heads and i had to change the springs. the cam was an old 350hp grind from the 60s like .450 lift. that rating i believe is for the 327 motors. the car ran well with that cam and the factory heads but wasnt making over 300hp.

if your heads arent decent that would be the first thing i would change. you can get vortecs for cheap and with the lift youre running shouldnt have an issue with the factory springs. on headers i would run long tubes, small diameter(1 5/8) to help with torque. dynomax makes a pair that are super cheap, but good. they can be had for under a hundred bucks. roller rockers are nice, but even cheap ones are pricey and probably close to half the price of a set of jy vortecs. harland sharps are affordable and good, i run scorpions also affordable and good.

on the 260hp thing. its always possible. if thats the rating they gave that motor i would think that it either already had a decent cam in it or has decent heads on it. after the very early 70s all of the small blocks became sub 200hp motors and didnt improve very much till the late 80s. the exception would be truck motors, but even they werent making 260hp. best of luck with the car, and post pics of it.