Right now I have a 402 10 to 1 612 lift solid cam je forged pistons steel crank with some built 781 cast heads but it's only 225 valves rpm air gap with a 800 demon on top roller rockers 1to 7 now I just bought some dart aluminum heads pro 1 230 1.88 valves do I with my 402 or I have a chance to buy a fresh 427 short block 2 bolt girdles steel crank and hyp pistons from Keith black 12 to one with a Hyd cam and lifters and put in on it and do a engine swap do u guys think it's worth the extra 1500 for the short block and 25 more cubic inches or keep the 402 its in a 88 trans am

 

Sounds like your current motor has a better bottom end in it with the forged pistons. I'd say just swap the heads/cam on the 402. It should pick up some power over stock castings.

What size Pro 1's you get?

 

Yeah-the 402 does sound like a better engine.You sound like a guy that has accepted the costs for a BBC build.So how about going to play with the 402 and sock money away for a future aftermarket block build??. Even if you have to pc it together over a long period of time.Shop for good deals.They are out there and becoming more common as time goes by.

Looking forward to reading about this build.

 

My 402 now will turn 8500 without a lick of problems So I'm thinking the darts will lot the thing really shine ESP with nos on reason with us the 427 short block isn't a bad deal ESP since it's already together I have a buddy with a 04 zo6 I wanna beat cause I hate losing I got a full susp set up 411s and a t56 and the 402 pushes a lil over 500 now so head swap and nos 2 stage 300 shot think I got a chance ?

 

If your motor has a decent cam (turning 8500 would imply a very big cam) and half decent heads, it should already make enough power to beat a 04 z06....unless he's not stock. They are high 11 second cars at 115mph give or take a few. Some have gone mid 11's at 118 in cold air and well driven.

If you put better heads on with port matched intake, it should make 600hp fairly easily and will run high 10's without too much effort. BBC's run pretty good with decent heads and cam. 300 shot on top of that, thats a low 9 second car. ZR1 wont touch that

 

He's got a sts single turbo I know he's runs mid 10s. I'm running high to high 10s low 11s on motor I hook up ver well still playing with my jets on my carb so looks like labor day weekend I'll be tearing my motor down I'll take some pics and post

 

Oh well then you are running pretty good as is, i'd just swap heads and retune for the higher air flow. Should pick up a decent amount. Hopefully get mid lower 10's

 

2.19 valves need a notch in the block to clear the 4.125" bore, let alone 2.25" or 2.30". While you might gain a little with the improved ports & chambers of the Darts, their full potential will be limited by the smaller bore.

If you're only 10:1 with the 781's, what are the chambers of the Darts? Will you lose compression?

I'd tend toward the 427 shortblock, personally (with a different cam, of course). As long as you aren't boosting or spraying it, the hyper pistons should be fine. You need to understand exactly what pop-up the pistons have, though, and how they'd play with the Dart chambers.

 

I talked to a tech at dart I'll still be around 10to 1 and the 225 will clear but I'll be picking up alot more flow in the exhaust side and I'm gonna stick with the 402 so I can stay on spray