Okay i have a 74 maverick grabber .30 302. It has long tubes, dual exaust, 289 eldbrock intake, holley carb, aod tranny, hood scoop. How much HP do you think i make as is ? Also please tell me how i can peak the 400 hp range and how much those parts would cost, 331 or 347 etc...... ?
depending on the cam heads and compression im thinking your probably at 250hp for a stroker rebuild your probably looking at $3k
If it is a stock long block, i'd guess 200 also. Cam and heads would probably bump it up a bit. Also depends on what,intake and carb. Remember you need to upgrade the electrical parts too. The whole thing needs to be done as a complete system. 400HP dosen't do any good if you don't have the rear and gears, and suspension to handle it.
If you have the original 74 block (D4 casting) it has a higher deck height than earlier and later (D8-up) blocks that lowers compression. If you mean 400 hp at the flywheel, a good set of heads, AFRs, TFs, etc., matching cam and compression boost will get your 302 there while maybe loosing some street manners. A stroker or 351 will do it easily but you will definitely need better heads and cam for the bigger displacement. Back when I built a 347 the rotating assembly was $900, block machine work was about $550, balancing was $275. I did the assembly myself, if you have to pay a shop add a couple hundred more. If your engine's in good shape you might want to look at just supercharging it.
What they all said, plus my 2 cents... You won't get a great deal of power from that intake manifold, and a "Holley" carb like you say can mean anything. You are doing good to have headers, free flow exhaust, and a good electronic ignition. Add that intake, a middle of the road Holley, and you didn't tell us about a cam... you probably make 200hp flywheel, without knowing anything else about your combo. With a 20% parasitic loss to the AOD, that is about 160 rwhp. To get the power you are looking for with a 302, you will lose street manners and need some serious head work... either that or some good aftermarket heads.
Good intake, carb and ignition system with what you have now will get you in the 300 range. This can be done for around a grand (new) or shop till you drop on e-bay etc. etc. The AOD is hurting your RWHP......but if this is a driver, I would live with that. *You did not mention what muffler you had.....this could be a point to address. IF this is a race car.....weight, weight and more weight
I am like you and think that we don't have nearly enough info. On the issue of weight, while it is out there, and the thread author hasn't given us a reason to disregard the subject... Have you found the old formula: 100lbs = tenth of a second 1/4 mile = 10 rwhp to be true? Is it a good rule of thumb? Or does it not work at all in your experience because of all the variables? I just wanted to get a racer's view on it. I hear the formula used alot, or did anyway, so I parrot it. If the real racers don't find it true, I would hate to keep throwing it out.
I think that formula is true to a point. Maybe be worth more in a car that is heavy and slow, may not be as much for a car that is already light and fast In circle track circles I have heard for every 7 lbs. lost, you gain 1 horsepower so I am sure all these formula's are like anything else we hear/read.....its good to within +- at certain %.
to get 400 HP out of a 302, you will need to: Raise the compression (new pistons - forged or at least hyper) Replace the heads (AFR 185 or similar) New cam and kit (a racing cam and kit w/ lifters, rockers, retainers, springs, locks, and pushrods) Roller timing chain and sprockets Stronger connecting rods and bolts Windage tray Intake and carb (for the higher RPM) Distributor and ignition system (or DSII rebuilt and recurved) ============================================ Or you could spend the money on a stroker kit which will give you a more street friendly 400 HP ============================================ Or you could build a blower motor ============================================ Or you could build a nitrous engine There is no inexpensive way to get 400 HP out of 302 cubic inches. It is unlikely that a stock block will stand up to a stock stroke 400 hp. It would be cheaper in the log run to swap in a larger displacement engine and tune it for the 400HP.
400HP is a piece of cake -------if you start with a stock roller shortblock. Either one from an 88-95 Mustang, or a 93-97 Pickup or van. It has been done with the stock HO roller cam and topped with AFR185 heads. And it's reached in the 6000-7000 rpm range. With the pickup/van 5.0. you also need to change the cam (unless you use the 94-97 Pickup/van cam with 1.7 rockers)
Yeah, it's even easier to get that power with a 347. Shamefully easy with a 393w or 408w... and for the same or less money.
agree....if I ever build another motor, it will be W based.....mainly due to less stress on the block to get the same #'s that a 302 would have. Lower compression and pump gas
