Fox 351w

I have seen a limited number of stock block applications where the owner put a huge amount of boost through a stock 302 block and shifted it really low and was able to crank out 900hp to the wheels. The most infamous was a black SN in Texas that did it consistently. I certainly wouldn't recommend trying this to anyone myself. Some people try stuff just to see what they can get away with. I have a friend with a 94' Camaro LT1. He got it to run 11.0 with stock ported heads with a 396 stroker kit and a stock 2 bolt main. He put an enormous cam on it, and shifted it at 8500 rpms. Every time it would eat the valve train, I would ask him why he didn't get some big AFRs and a smaller cam. He would always laugh and say, "I just want to see how far I can go without buying new heads." He just kept rebuilding the valve train year after year.

My last stock block stroker engine made it 10 years and 85,000 miles putting 492/635 to the wheels. That's pretty close to 600/700 at the crank, on a stock 93' roller block. It finally broke due to a bearing failure. Totally unrelated to a block failure. Did I get lucky? Was it a really well balanced engine? Who knows. In fact when the new engine builder took some of it apart, he found some errors the original engine builder had made. The wrist pins were too tight, and the valve springs weren't strong enough. I had also used stock bottom end hardware on it. I hope my new engine does that well. I certainly put more money into it, and built it better than the last one. I can say that of the stock block failures I have seen, I would cut the causes into 3rds. One 3rd put way too much power into it and cracked the block. One 3rd put inferior quality Chinese parts in it and cracked the block. One 3rd did everything right and hey, the block just cracked.

I had a friend run 3 seasons on a stock block 347 on nitrous. He decided to go to a 351W block for the next season when they allowed it. He parked his stock block 347 on an engine stand. It ran similar times to his 347, and then the block cracked after two events. He got rid of that block and built a Man O War 347. It made it half a season, and the block cracked. He pulled the old 2 bolt 347 off the stand and put it back in the car, finished that season, and ran another season after that. Sometimes it's just complete luck of the draw on engines. The car is now parked with that engine. Family and work caught up to him.

I can tell you exactly why the 351C had 4 bolt mains. It was the performance engine of the time. They were putting that engine in the higher performance cars in the early 70s. Just like I said before, the Ws and Ms were going in the trucks, the Cs were going in the Mustangs.

Whenever you look at a stock engine, always ask yourself what it was used for in stock form. None of the stock engines Ford has ever used had any substantial block failures. They were all over engineered for their intended purpose.

The 351W does have more meat in the bottom where it counts. I would say it's good for an extra 100hp. That's my best guess. I can tell you that I have built many engines, and it's hands down cheaper to build a 4 bolt 302 over a stock block 351. The nickel and dime parts to convert a car to a 351 just add up so quick.

My engine builder hands down refutes that any particular 302 block is better than any other. He's been building serious engines for 40 years now. He has always been adamant that these rumors of Mexican blocks are based on information that has been handed down for 30 years now. Back in 1980 you were better off going out and finding the blocks cast in Mexico because they had a higher nickel content. However, today it is far better to go with a newer block. The killer of SBFs is miles. They are life limited parts, and they fatigue out. When we built my engine, he specifically found a block cast in 2004 with almost no miles on it. He still thought I should go with a 4 bolt main, but he said this block will give me the best odds.

Ok, now I'm just rambling

Kurt